diff --git a/.github/workflows/php.yml b/.github/workflows/php.yml
index a89cd72..bfe41a5 100644
--- a/.github/workflows/php.yml
+++ b/.github/workflows/php.yml
@@ -19,7 +19,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php-version: ['8.3', '8.4', '8.5']
+        php-version: ['8.5']
 
     uses: simplesamlphp/simplesamlphp-test-framework/.github/workflows/reusable_phplinter.yml@v1
     secrets: inherit
@@ -47,7 +47,7 @@ jobs:
       fail-fast: false
       matrix:
         operating-system: [ubuntu-latest]
-        php-versions: ['8.3', '8.4', '8.5']
+        php-versions: ['8.5']
 
     steps:
       - name: Setup PHP, with composer and extensions
@@ -109,7 +109,7 @@ jobs:
       fail-fast: true
       matrix:
         operating-system: [windows-latest]
-        php-versions: ['8.3', '8.4', '8.5']
+        php-versions: ['8.5']
 
     steps:
       - name: Setup PHP, with composer and extensions
@@ -217,7 +217,7 @@ jobs:
         uses: shivammathur/setup-php@v2
         with:
           # Should be the lowest supported version
-          php-version: '8.3'
+          php-version: '8.5'
           extensions: ctype, date, dom, filter, pcre, soap, spl, xml
           tools: composer
           coverage: none
diff --git a/composer.json b/composer.json
index 6616871..c22421b 100644
--- a/composer.json
+++ b/composer.json
@@ -9,12 +9,12 @@
         }
     ],
     "require": {
-        "php": "^8.3",
+        "php": "^8.5",
         "ext-dom": "*",
         "ext-spl": "*",
 
         "simplesamlphp/assert": "~2.0",
-        "simplesamlphp/xml-common": "~2.8"
+        "simplesamlphp/xml-common": "dev-feature/dom-migration-php84"
     },
     "require-dev": {
         "simplesamlphp/simplesamlphp-test-framework": "~1.11"
@@ -42,5 +42,19 @@
             "simplesamlphp/composer-xmlprovider-installer": true,
             "simplesamlphp/composer-module-installer": true
         }
+    },
+    "scripts": {
+        "pre-commit": [
+            "vendor/bin/phpcs -p",
+            "vendor/bin/phpstan analyze -c phpstan.neon",
+            "vendor/bin/phpstan analyze -c phpstan-dev.neon",
+            "vendor/bin/phpunit --no-coverage --testdox"
+        ],
+        "tests": [
+            "vendor/bin/phpunit --no-coverage"
+        ],
+        "propose-fix": [
+            "vendor/bin/phpcs --report=diff"
+        ]
     }
 }
diff --git a/src/Utils/XPath.php b/src/Utils/XPath.php
index dc375ec..d03911e 100644
--- a/src/Utils/XPath.php
+++ b/src/Utils/XPath.php
@@ -4,8 +4,7 @@
 
 namespace SimpleSAML\WSDL\Utils;
 
-use DOMNode;
-use DOMXPath;
+use Dom;
 use SimpleSAML\WSDL\Constants as C;
 use SimpleSAML\XPath\XPath as XPathUtils;
 
@@ -17,15 +16,15 @@
 class XPath extends XPathUtils
 {
     /**
-     * Get a DOMXPath object that can be used to search for XMLDSIG elements.
+     * Get a Dom\XPath object that can be used to search for XMLDSIG elements.
      *
-     * @param \DOMNode $node The document to associate to the DOMXPath object.
+     * @param \Dom\Node $node The document to associate to the Dom\XPath object.
      * @param bool $autoregister Whether to auto-register all namespaces used in the document
      *
-     * @return \DOMXPath A DOMXPath object ready to use in the given document, with the XMLDSIG namespace already
+     * @return \Dom\XPath A Dom\XPath object ready to use in the given document, with the XMLDSIG namespace already
      * registered.
      */
-    public static function getXPath(DOMNode $node, bool $autoregister = false): DOMXPath
+    public static function getXPath(Dom\Node $node, bool $autoregister = false): Dom\XPath
     {
         $xp = parent::getXPath($node, $autoregister);
 
diff --git a/src/XML/soap12/AbstractAddress.php b/src/XML/soap12/AbstractAddress.php
index 3bbd7cb..522a97b 100644
--- a/src/XML/soap12/AbstractAddress.php
+++ b/src/XML/soap12/AbstractAddress.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\soap12;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\Assert\Assert;
 use SimpleSAML\WSDL\Constants as C;
 use SimpleSAML\WSDL\Type\RequiredValue;
@@ -56,12 +56,12 @@ public function getLocation(): AnyURIValue
     /**
      * Initialize a Address element.
      *
-     * @param \DOMElement $xml The XML element we should load.
+     * @param \Dom\Element $xml The XML element we should load.
      *
      * @throws \SimpleSAML\XMLSchema\Exception\InvalidDOMElementException
      *   if the qualified name of the supplied element is wrong
      */
-    public static function fromXML(DOMElement $xml): static
+    public static function fromXML(Dom\Element $xml): static
     {
         Assert::same($xml->localName, static::getLocalName(), InvalidDOMElementException::class);
         Assert::same($xml->namespaceURI, static::NS, InvalidDOMElementException::class);
@@ -81,10 +81,10 @@ public static function fromXML(DOMElement $xml): static
     /**
      * Convert this tBinding to XML.
      *
-     * @param \DOMElement|null $parent The element we are converting to XML.
-     * @return \DOMElement The XML element after adding the data corresponding to this tBinding
+     * @param \Dom\Element|null $parent The element we are converting to XML.
+     * @return \Dom\Element The XML element after adding the data corresponding to this tBinding
      */
-    public function toXML(?DOMElement $parent = null): DOMElement
+    public function toXML(?Dom\Element $parent = null): Dom\Element
     {
         $e = parent::toXML($parent);
         $e->setAttribute('location', $this->getLocation()->getValue());
diff --git a/src/XML/soap12/AbstractBinding.php b/src/XML/soap12/AbstractBinding.php
index 28cb266..57dfe9c 100644
--- a/src/XML/soap12/AbstractBinding.php
+++ b/src/XML/soap12/AbstractBinding.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\soap12;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\Assert\Assert;
 use SimpleSAML\WSDL\Constants as C;
 use SimpleSAML\WSDL\Type\RequiredValue;
@@ -81,12 +81,12 @@ public function isEmptyElement(): bool
     /**
      * Initialize a Binding element.
      *
-     * @param \DOMElement $xml The XML element we should load.
+     * @param \Dom\Element $xml The XML element we should load.
      *
      * @throws \SimpleSAML\XMLSchema\Exception\InvalidDOMElementException
      *   if the qualified name of the supplied element is wrong
      */
-    public static function fromXML(DOMElement $xml): static
+    public static function fromXML(Dom\Element $xml): static
     {
         Assert::same($xml->localName, static::getLocalName(), InvalidDOMElementException::class);
         Assert::same($xml->namespaceURI, static::NS, InvalidDOMElementException::class);
@@ -107,10 +107,10 @@ public static function fromXML(DOMElement $xml): static
     /**
      * Convert this tBinding to XML.
      *
-     * @param \DOMElement|null $parent The element we are converting to XML.
-     * @return \DOMElement The XML element after adding the data corresponding to this tBinding
+     * @param \Dom\Element|null $parent The element we are converting to XML.
+     * @return \Dom\Element The XML element after adding the data corresponding to this tBinding
      */
-    public function toXML(?DOMElement $parent = null): DOMElement
+    public function toXML(?Dom\Element $parent = null): Dom\Element
     {
         $e = parent::toXML($parent);
 
diff --git a/src/XML/soap12/AbstractBody.php b/src/XML/soap12/AbstractBody.php
index 737588f..d71525b 100644
--- a/src/XML/soap12/AbstractBody.php
+++ b/src/XML/soap12/AbstractBody.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\soap12;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\WSDL\Constants as C;
 use SimpleSAML\WSDL\Type\RequiredValue;
 use SimpleSAML\WSDL\Type\UseChoiceValue;
@@ -83,10 +83,10 @@ public function isEmptyElement(): bool
     /**
      * Convert this tBody to XML.
      *
-     * @param \DOMElement|null $parent The element we are converting to XML.
-     * @return \DOMElement The XML element after adding the data corresponding to this tBody
+     * @param \Dom\Element|null $parent The element we are converting to XML.
+     * @return \Dom\Element The XML element after adding the data corresponding to this tBody
      */
-    public function toXML(?DOMElement $parent = null): DOMElement
+    public function toXML(?Dom\Element $parent = null): Dom\Element
     {
         $e = parent::toXML($parent);
 
diff --git a/src/XML/soap12/AbstractFault.php b/src/XML/soap12/AbstractFault.php
index b0581b5..39ed220 100644
--- a/src/XML/soap12/AbstractFault.php
+++ b/src/XML/soap12/AbstractFault.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\soap12;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\Assert\Assert;
 use SimpleSAML\WSDL\Constants as C;
 use SimpleSAML\WSDL\Type\RequiredValue;
@@ -49,12 +49,12 @@ final public function __construct(
     /**
      * Initialize a Body element.
      *
-     * @param \DOMElement $xml The XML element we should load.
+     * @param \Dom\Element $xml The XML element we should load.
      *
      * @throws \SimpleSAML\XMLSchema\Exception\InvalidDOMElementException
      *   if the qualified name of the supplied element is wrong
      */
-    public static function fromXML(DOMElement $xml): static
+    public static function fromXML(Dom\Element $xml): static
     {
         Assert::same($xml->localName, static::getLocalName(), InvalidDOMElementException::class);
         Assert::same($xml->namespaceURI, static::NS, InvalidDOMElementException::class);
@@ -76,10 +76,10 @@ public static function fromXML(DOMElement $xml): static
     /**
      * Convert this tFault to XML.
      *
-     * @param \DOMElement|null $parent The element we are converting to XML.
-     * @return \DOMElement The XML element after adding the data corresponding to this tFault
+     * @param \Dom\Element|null $parent The element we are converting to XML.
+     * @return \Dom\Element The XML element after adding the data corresponding to this tFault
      */
-    public function toXML(?DOMElement $parent = null): DOMElement
+    public function toXML(?Dom\Element $parent = null): Dom\Element
     {
         return parent::toXML($parent);
     }
diff --git a/src/XML/soap12/AbstractHeader.php b/src/XML/soap12/AbstractHeader.php
index 14c9d6e..f921285 100644
--- a/src/XML/soap12/AbstractHeader.php
+++ b/src/XML/soap12/AbstractHeader.php
@@ -4,12 +4,14 @@
 
 namespace SimpleSAML\WSDL\XML\soap12;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\Assert\Assert;
-use SimpleSAML\WSDL\Constants as C;
+use SimpleSAML\WSDL\Constants as C_WSDL;
 use SimpleSAML\WSDL\Type\RequiredValue;
 use SimpleSAML\WSDL\Type\UseChoiceValue;
 use SimpleSAML\WSDL\XML\wsdl\AbstractExtensibilityElement;
+use SimpleSAML\XML\Attribute as XMLAttribute;
+use SimpleSAML\XML\Constants as C;
 use SimpleSAML\XMLSchema\Exception\InvalidDOMElementException;
 use SimpleSAML\XMLSchema\Exception\SchemaViolationException;
 use SimpleSAML\XMLSchema\Type\AnyURIValue;
@@ -26,7 +28,7 @@ abstract class AbstractHeader extends AbstractExtensibilityElement
     use BodyAttributesTrait;
 
 
-    public const string NS = C::NS_WSDL_SOAP_12;
+    public const string NS = C_WSDL::NS_WSDL_SOAP_12;
 
     public const string NS_PREFIX = 'soap12';
 
@@ -102,19 +104,19 @@ public function getParts(): ?NMTokensValue
     /**
      * Initialize a Header element.
      *
-     * @param \DOMElement $xml The XML element we should load.
+     * @param \Dom\Element $xml The XML element we should load.
      *
      * @throws \SimpleSAML\XMLSchema\Exception\InvalidDOMElementException
      *   if the qualified name of the supplied element is wrong
      */
-    public static function fromXML(DOMElement $xml): static
+    public static function fromXML(Dom\Element $xml): static
     {
         Assert::same($xml->localName, static::getLocalName(), InvalidDOMElementException::class);
         Assert::same($xml->namespaceURI, static::NS, InvalidDOMElementException::class);
 
         $required = null;
-        if ($xml->hasAttributeNS(C::NS_WSDL, 'required')) {
-            $required = RequiredValue::fromString($xml->getAttributeNS(C::NS_WSDL, 'required'));
+        if ($xml->hasAttributeNS(C_WSDL::NS_WSDL, 'required')) {
+            $required = RequiredValue::fromString($xml->getAttributeNS(C_WSDL::NS_WSDL, 'required'));
         }
 
         return new static(
@@ -132,13 +134,23 @@ public static function fromXML(DOMElement $xml): static
     /**
      * Convert this tHeader to XML.
      *
-     * @param \DOMElement|null $parent The element we are converting to XML.
-     * @return \DOMElement The XML element after adding the data corresponding to this tHeader
+     * @param \Dom\Element|null $parent The element we are converting to XML.
+     * @return \Dom\Element The XML element after adding the data corresponding to this tHeader
      */
-    public function toXML(?DOMElement $parent = null): DOMElement
+    public function toXML(?Dom\Element $parent = null): Dom\Element
     {
         $e = parent::toXML($parent);
 
+        if (!$e->lookupPrefix($this->getMessage()->getNamespacePrefix()->getValue())) {
+            $namespace = new XMLAttribute(
+                C::NS_XMLNS,
+                'xmlns',
+                $this->getMessage()->getNamespacePrefix()->getValue(),
+                $this->getMessage()->getNamespaceURI(),
+            );
+            $namespace->toXML($e);
+        }
+
         $e->setAttribute('message', $this->getMessage()->getValue());
         $e->setAttribute('parts', $this->getParts()->getValue());
         $e->setAttribute('use', $this->getUse()->getValue());
diff --git a/src/XML/soap12/AbstractHeaderFault.php b/src/XML/soap12/AbstractHeaderFault.php
index e35d593..2d5b825 100644
--- a/src/XML/soap12/AbstractHeaderFault.php
+++ b/src/XML/soap12/AbstractHeaderFault.php
@@ -4,9 +4,11 @@
 
 namespace SimpleSAML\WSDL\XML\soap12;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\WSDL\Assert\Assert;
 use SimpleSAML\WSDL\Type\UseChoiceValue;
+use SimpleSAML\XML\Attribute as XMLAttribute;
+use SimpleSAML\XML\Constants as C;
 use SimpleSAML\XMLSchema\Exception\InvalidDOMElementException;
 use SimpleSAML\XMLSchema\Type\AnyURIValue;
 use SimpleSAML\XMLSchema\Type\NMTokensValue;
@@ -73,12 +75,12 @@ public function getParts(): ?NMTokensValue
     /**
      * Initialize a Header element.
      *
-     * @param \DOMElement $xml The XML element we should load.
+     * @param \Dom\Element $xml The XML element we should load.
      *
      * @throws \SimpleSAML\XMLSchema\Exception\InvalidDOMElementException
      *   if the qualified name of the supplied element is wrong
      */
-    public static function fromXML(DOMElement $xml): static
+    public static function fromXML(Dom\Element $xml): static
     {
         Assert::same($xml->localName, static::getLocalName(), InvalidDOMElementException::class);
         Assert::same($xml->namespaceURI, static::NS, InvalidDOMElementException::class);
@@ -96,13 +98,23 @@ public static function fromXML(DOMElement $xml): static
     /**
      * Convert this tHeader to XML.
      *
-     * @param \DOMElement|null $parent The element we are converting to XML.
-     * @return \DOMElement The XML element after adding the data corresponding to this tHeader
+     * @param \Dom\Element|null $parent The element we are converting to XML.
+     * @return \Dom\Element The XML element after adding the data corresponding to this tHeader
      */
-    public function toXML(?DOMElement $parent = null): DOMElement
+    public function toXML(?Dom\Element $parent = null): Dom\Element
     {
         $e = $this->instantiateParentElement($parent);
 
+        if (!$e->lookupPrefix($this->getMessage()->getNamespacePrefix()->getValue())) {
+            $namespace = new XMLAttribute(
+                C::NS_XMLNS,
+                'xmlns',
+                $this->getMessage()->getNamespacePrefix()->getValue(),
+                $this->getMessage()->getNamespaceURI(),
+            );
+            $namespace->toXML($e);
+        }
+
         $e->setAttribute('message', $this->getMessage()->getValue());
         $e->setAttribute('parts', $this->getParts()->getValue());
         $e->setAttribute('use', $this->getUse()->getValue());
diff --git a/src/XML/soap12/AbstractOperation.php b/src/XML/soap12/AbstractOperation.php
index 539a7d4..1e07e80 100644
--- a/src/XML/soap12/AbstractOperation.php
+++ b/src/XML/soap12/AbstractOperation.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\soap12;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\Assert\Assert;
 use SimpleSAML\WSDL\Constants as C;
 use SimpleSAML\WSDL\Type\RequiredValue;
@@ -96,12 +96,12 @@ public function isEmptyElement(): bool
     /**
      * Initialize an Operation element.
      *
-     * @param \DOMElement $xml The XML element we should load.
+     * @param \Dom\Element $xml The XML element we should load.
      *
      * @throws \SimpleSAML\XMLSchema\Exception\InvalidDOMElementException
      *   if the qualified name of the supplied element is wrong
      */
-    public static function fromXML(DOMElement $xml): static
+    public static function fromXML(Dom\Element $xml): static
     {
         Assert::same($xml->localName, static::getLocalName(), InvalidDOMElementException::class);
         Assert::same($xml->namespaceURI, static::NS, InvalidDOMElementException::class);
@@ -123,10 +123,10 @@ public static function fromXML(DOMElement $xml): static
     /**
      * Convert this tOperation to XML.
      *
-     * @param \DOMElement|null $parent The element we are converting to XML.
-     * @return \DOMElement The XML element after adding the data corresponding to this tOperation
+     * @param \Dom\Element|null $parent The element we are converting to XML.
+     * @return \Dom\Element The XML element after adding the data corresponding to this tOperation
      */
-    public function toXML(?DOMElement $parent = null): DOMElement
+    public function toXML(?Dom\Element $parent = null): Dom\Element
     {
         $e = parent::toXML($parent);
 
diff --git a/src/XML/soap12/Body.php b/src/XML/soap12/Body.php
index 01b5305..be506c0 100644
--- a/src/XML/soap12/Body.php
+++ b/src/XML/soap12/Body.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\soap12;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\Assert\Assert;
 use SimpleSAML\WSDL\Constants as C;
 use SimpleSAML\WSDL\Type\RequiredValue;
@@ -28,12 +28,12 @@ final class Body extends AbstractBody implements SchemaValidatableElementInterfa
     /**
      * Initialize a Body element.
      *
-     * @param \DOMElement $xml The XML element we should load.
+     * @param \Dom\Element $xml The XML element we should load.
      *
      * @throws \SimpleSAML\XMLSchema\Exception\InvalidDOMElementException
      *   if the qualified name of the supplied element is wrong
      */
-    public static function fromXML(DOMElement $xml): static
+    public static function fromXML(Dom\Element $xml): static
     {
         Assert::same($xml->localName, static::getLocalName(), InvalidDOMElementException::class);
         Assert::same($xml->namespaceURI, static::NS, InvalidDOMElementException::class);
diff --git a/src/XML/wsdl/AbstractBinding.php b/src/XML/wsdl/AbstractBinding.php
index 95a728c..33391a8 100644
--- a/src/XML/wsdl/AbstractBinding.php
+++ b/src/XML/wsdl/AbstractBinding.php
@@ -4,8 +4,10 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\WSDL\Assert\Assert;
+use SimpleSAML\XML\Attribute as XMLAttribute;
+use SimpleSAML\XML\Constants as C;
 use SimpleSAML\XMLSchema\Exception\SchemaViolationException;
 use SimpleSAML\XMLSchema\Type\NCNameValue;
 use SimpleSAML\XMLSchema\Type\QNameValue;
@@ -73,14 +75,26 @@ public function getOperation(): array
     /**
      * Convert this tBinding to XML.
      *
-     * @param \DOMElement|null $parent The element we are converting to XML.
-     * @return \DOMElement The XML element after adding the data corresponding to this tBinding.
+     * @param \Dom\Element|null $parent The element we are converting to XML.
+     * @return \Dom\Element The XML element after adding the data corresponding to this tBinding.
      */
-    public function toXML(?DOMElement $parent = null): DOMElement
+    public function toXML(?Dom\Element $parent = null): Dom\Element
     {
         $e = parent::toXML($parent);
 
         $e->setAttribute('name', $this->getName()->getValue());
+
+
+        if (!$e->lookupPrefix($this->getType()->getNamespacePrefix()->getValue())) {
+            $namespace = new XMLAttribute(
+                C::NS_XMLNS,
+                'xmlns',
+                $this->getType()->getNamespacePrefix()->getValue(),
+                $this->getType()->getNamespaceURI(),
+            );
+            $namespace->toXML($e);
+        }
+
         $e->setAttribute('type', $this->getType()->getValue());
 
         foreach ($this->getOperation() as $operation) {
diff --git a/src/XML/wsdl/AbstractBindingOperation.php b/src/XML/wsdl/AbstractBindingOperation.php
index cbc529b..c098432 100644
--- a/src/XML/wsdl/AbstractBindingOperation.php
+++ b/src/XML/wsdl/AbstractBindingOperation.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\WSDL\Assert\Assert;
 use SimpleSAML\XMLSchema\Exception\SchemaViolationException;
 use SimpleSAML\XMLSchema\Type\NCNameValue;
@@ -95,10 +95,10 @@ public function isEmptyElement(): bool
     /**
      * Convert this tBindingOperation to XML.
      *
-     * @param \DOMElement|null $parent The element we are converting to XML.
-     * @return \DOMElement The XML element after adding the data corresponding to this tBindingOperation.
+     * @param \Dom\Element|null $parent The element we are converting to XML.
+     * @return \Dom\Element The XML element after adding the data corresponding to this tBindingOperation.
      */
-    public function toXML(?DOMElement $parent = null): DOMElement
+    public function toXML(?Dom\Element $parent = null): Dom\Element
     {
         $e = parent::toXML($parent);
 
diff --git a/src/XML/wsdl/AbstractBindingOperationFault.php b/src/XML/wsdl/AbstractBindingOperationFault.php
index 83f3cec..b143b1a 100644
--- a/src/XML/wsdl/AbstractBindingOperationFault.php
+++ b/src/XML/wsdl/AbstractBindingOperationFault.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\XMLSchema\Type\NCNameValue;
 
 /**
@@ -52,10 +52,10 @@ public function isEmptyElement(): bool
     /**
      * Convert this tBindingOperationFault to XML.
      *
-     * @param \DOMElement|null $parent The element we are converting to XML.
-     * @return \DOMElement The XML element after adding the data corresponding to this tBindingOperationFault.
+     * @param \Dom\Element|null $parent The element we are converting to XML.
+     * @return \Dom\Element The XML element after adding the data corresponding to this tBindingOperationFault.
      */
-    public function toXML(?DOMElement $parent = null): DOMElement
+    public function toXML(?Dom\Element $parent = null): Dom\Element
     {
         $e = parent::toXML($parent);
         $e->setAttribute('name', $this->getName()->getValue());
diff --git a/src/XML/wsdl/AbstractBindingOperationMessage.php b/src/XML/wsdl/AbstractBindingOperationMessage.php
index 543962d..202a764 100644
--- a/src/XML/wsdl/AbstractBindingOperationMessage.php
+++ b/src/XML/wsdl/AbstractBindingOperationMessage.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\XMLSchema\Type\NCNameValue;
 
 /**
@@ -51,10 +51,10 @@ public function isEmptyElement(): bool
     /**
      * Convert this tBindingOperationMessage to XML.
      *
-     * @param \DOMElement|null $parent The element we are converting to XML.
-     * @return \DOMElement The XML element after adding the data corresponding to this tBindingOperationMessage.
+     * @param \Dom\Element|null $parent The element we are converting to XML.
+     * @return \Dom\Element The XML element after adding the data corresponding to this tBindingOperationMessage.
      */
-    public function toXML(?DOMElement $parent = null): DOMElement
+    public function toXML(?Dom\Element $parent = null): Dom\Element
     {
         $e = parent::toXML($parent);
 
diff --git a/src/XML/wsdl/AbstractDefinitions.php b/src/XML/wsdl/AbstractDefinitions.php
index 1c12a92..82b2906 100644
--- a/src/XML/wsdl/AbstractDefinitions.php
+++ b/src/XML/wsdl/AbstractDefinitions.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\WSDL\Assert\Assert;
 use SimpleSAML\XMLSchema\Exception\SchemaViolationException;
 use SimpleSAML\XMLSchema\Type\AnyURIValue;
@@ -222,10 +222,10 @@ public function isEmptyElement(): bool
     /**
      * Convert this tDefinitions to XML.
      *
-     * @param \DOMElement|null $parent The element we are converting to XML.
-     * @return \DOMElement The XML element after adding the data corresponding to this tDefinitions.
+     * @param \Dom\Element|null $parent The element we are converting to XML.
+     * @return \Dom\Element The XML element after adding the data corresponding to this tDefinitions.
      */
-    public function toXML(?DOMElement $parent = null): DOMElement
+    public function toXML(?Dom\Element $parent = null): Dom\Element
     {
         $e = parent::toXML($parent);
 
diff --git a/src/XML/wsdl/AbstractDocumented.php b/src/XML/wsdl/AbstractDocumented.php
index 8473d9d..f7fd1a3 100644
--- a/src/XML/wsdl/AbstractDocumented.php
+++ b/src/XML/wsdl/AbstractDocumented.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
 
 /**
  * Abstract class representing the tDocumented type.
@@ -47,10 +47,10 @@ public function isEmptyElement(): bool
     /**
      * Convert this tDocumented to XML.
      *
-     * @param \DOMElement|null $parent The element we are converting to XML.
-     * @return \DOMElement The XML element after adding the data corresponding to this tDocumented.
+     * @param \Dom\Element|null $parent The element we are converting to XML.
+     * @return \Dom\Element The XML element after adding the data corresponding to this tDocumented.
      */
-    public function toXML(?DOMElement $parent = null): DOMElement
+    public function toXML(?Dom\Element $parent = null): Dom\Element
     {
         $e = $this->instantiateParentElement($parent);
 
diff --git a/src/XML/wsdl/AbstractExtensibilityElement.php b/src/XML/wsdl/AbstractExtensibilityElement.php
index 7688595..9dba6d3 100644
--- a/src/XML/wsdl/AbstractExtensibilityElement.php
+++ b/src/XML/wsdl/AbstractExtensibilityElement.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\WSDL\Type\RequiredValue;
 
 /**
@@ -48,10 +48,10 @@ public function isEmptyElement(): bool
     /**
      * Convert this tExtensibilityElement to XML.
      *
-     * @param \DOMElement|null $parent The element we are converting to XML.
-     * @return \DOMElement The XML element after adding the data corresponding to this tExtensibilityElement
+     * @param \Dom\Element|null $parent The element we are converting to XML.
+     * @return \Dom\Element The XML element after adding the data corresponding to this tExtensibilityElement
      */
-    public function toXML(?DOMElement $parent = null): DOMElement
+    public function toXML(?Dom\Element $parent = null): Dom\Element
     {
         $e = $this->instantiateParentElement($parent);
         $this->getRequired()?->toAttribute()->toXML($e);
diff --git a/src/XML/wsdl/AbstractExtensibleAttributesDocumented.php b/src/XML/wsdl/AbstractExtensibleAttributesDocumented.php
index 7ef6847..2fadf82 100644
--- a/src/XML/wsdl/AbstractExtensibleAttributesDocumented.php
+++ b/src/XML/wsdl/AbstractExtensibleAttributesDocumented.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\XML\ExtendableAttributesTrait;
 use SimpleSAML\XMLSchema\XML\Constants\NS;
 
@@ -46,10 +46,10 @@ public function isEmptyElement(): bool
     /**
      * Convert this tExtensibleAttributesDocumented to XML.
      *
-     * @param \DOMElement|null $parent The element we are converting to XML.
-     * @return \DOMElement The XML element after adding the data corresponding to this tExtensibleAttributesDocumented.
+     * @param \Dom\Element|null $parent The element we are converting to XML.
+     * @return \Dom\Element The XML element after adding the data corresponding to this tExtensibleAttributesDocumented.
      */
-    public function toXML(?DOMElement $parent = null): DOMElement
+    public function toXML(?Dom\Element $parent = null): Dom\Element
     {
         $e = parent::toXML($parent);
 
diff --git a/src/XML/wsdl/AbstractExtensibleDocumented.php b/src/XML/wsdl/AbstractExtensibleDocumented.php
index b66c340..1f09db5 100644
--- a/src/XML/wsdl/AbstractExtensibleDocumented.php
+++ b/src/XML/wsdl/AbstractExtensibleDocumented.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\XML\ExtendableElementTrait;
 use SimpleSAML\XMLSchema\XML\Constants\NS;
 
@@ -46,10 +46,10 @@ public function isEmptyElement(): bool
     /**
      * Convert this tExtensibleDocumented to XML.
      *
-     * @param \DOMElement|null $parent The element we are converting to XML.
-     * @return \DOMElement The XML element after adding the data corresponding to this tExtensibleDocumented.
+     * @param \Dom\Element|null $parent The element we are converting to XML.
+     * @return \Dom\Element The XML element after adding the data corresponding to this tExtensibleDocumented.
      */
-    public function toXML(?DOMElement $parent = null): DOMElement
+    public function toXML(?Dom\Element $parent = null): Dom\Element
     {
         $e = parent::toXML($parent);
 
diff --git a/src/XML/wsdl/AbstractFault.php b/src/XML/wsdl/AbstractFault.php
index f6f15b1..22fd2df 100644
--- a/src/XML/wsdl/AbstractFault.php
+++ b/src/XML/wsdl/AbstractFault.php
@@ -4,7 +4,9 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
+use SimpleSAML\XML\Attribute as XMLAttribute;
+use SimpleSAML\XML\Constants as C;
 use SimpleSAML\XMLSchema\Type\NCNameValue;
 use SimpleSAML\XMLSchema\Type\QNameValue;
 
@@ -66,14 +68,25 @@ public function isEmptyElement(): bool
     /**
      * Convert this tParam to XML.
      *
-     * @param \DOMElement|null $parent The element we are converting to XML.
-     * @return \DOMElement The XML element after adding the data corresponding to this tParam.
+     * @param \Dom\Element|null $parent The element we are converting to XML.
+     * @return \Dom\Element The XML element after adding the data corresponding to this tParam.
      */
-    public function toXML(?DOMElement $parent = null): DOMElement
+    public function toXML(?Dom\Element $parent = null): Dom\Element
     {
         $e = parent::toXML($parent);
 
         $e->setAttribute('name', $this->getName()->getValue());
+
+        if (!$e->lookupPrefix($this->getMessage()->getNamespacePrefix()->getValue())) {
+            $namespace = new XMLAttribute(
+                C::NS_XMLNS,
+                'xmlns',
+                $this->getMessage()->getNamespacePrefix()->getValue(),
+                $this->getMessage()->getNamespaceURI(),
+            );
+            $namespace->toXML($e);
+        }
+
         $e->setAttribute('message', $this->getMessage()->getValue());
 
         return $e;
diff --git a/src/XML/wsdl/AbstractImport.php b/src/XML/wsdl/AbstractImport.php
index b4fe2d8..fbe4c66 100644
--- a/src/XML/wsdl/AbstractImport.php
+++ b/src/XML/wsdl/AbstractImport.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\XMLSchema\Type\AnyURIValue;
 
 /**
@@ -65,10 +65,10 @@ public function isEmptyElement(): bool
     /**
      * Convert this tImport to XML.
      *
-     * @param \DOMElement|null $parent The element we are converting to XML.
-     * @return \DOMElement The XML element after adding the data corresponding to this tImport.
+     * @param \Dom\Element|null $parent The element we are converting to XML.
+     * @return \Dom\Element The XML element after adding the data corresponding to this tImport.
      */
-    public function toXML(?DOMElement $parent = null): DOMElement
+    public function toXML(?Dom\Element $parent = null): Dom\Element
     {
         $e = parent::toXML($parent);
 
diff --git a/src/XML/wsdl/AbstractMessage.php b/src/XML/wsdl/AbstractMessage.php
index 31efd37..f4dfb96 100644
--- a/src/XML/wsdl/AbstractMessage.php
+++ b/src/XML/wsdl/AbstractMessage.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\WSDL\Assert\Assert;
 use SimpleSAML\XMLSchema\Exception\SchemaViolationException;
 use SimpleSAML\XMLSchema\Type\NCNameValue;
@@ -79,10 +79,10 @@ public function isEmptyElement(): bool
     /**
      * Convert this tParam to XML.
      *
-     * @param \DOMElement|null $parent The element we are converting to XML.
-     * @return \DOMElement The XML element after adding the data corresponding to this tParam.
+     * @param \Dom\Element|null $parent The element we are converting to XML.
+     * @return \Dom\Element The XML element after adding the data corresponding to this tParam.
      */
-    public function toXML(?DOMElement $parent = null): DOMElement
+    public function toXML(?Dom\Element $parent = null): Dom\Element
     {
         $e = parent::toXML($parent);
         $e->setAttribute('name', $this->getName()->getValue());
diff --git a/src/XML/wsdl/AbstractParam.php b/src/XML/wsdl/AbstractParam.php
index 0ac4d14..7030a8a 100644
--- a/src/XML/wsdl/AbstractParam.php
+++ b/src/XML/wsdl/AbstractParam.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\XMLSchema\Type\NCNameValue;
 use SimpleSAML\XMLSchema\Type\QNameValue;
 
@@ -66,10 +66,10 @@ public function isEmptyElement(): bool
     /**
      * Convert this tParam to XML.
      *
-     * @param \DOMElement|null $parent The element we are converting to XML.
-     * @return \DOMElement The XML element after adding the data corresponding to this tParam.
+     * @param \Dom\Element|null $parent The element we are converting to XML.
+     * @return \Dom\Element The XML element after adding the data corresponding to this tParam.
      */
-    public function toXML(?DOMElement $parent = null): DOMElement
+    public function toXML(?Dom\Element $parent = null): Dom\Element
     {
         $e = parent::toXML($parent);
 
diff --git a/src/XML/wsdl/AbstractPart.php b/src/XML/wsdl/AbstractPart.php
index d56945d..01f1f7f 100644
--- a/src/XML/wsdl/AbstractPart.php
+++ b/src/XML/wsdl/AbstractPart.php
@@ -4,7 +4,9 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
+use SimpleSAML\XML\Attribute as XMLAttribute;
+use SimpleSAML\XML\Constants as C;
 use SimpleSAML\XMLSchema\Type\NCNameValue;
 use SimpleSAML\XMLSchema\Type\QNameValue;
 
@@ -79,20 +81,40 @@ public function isEmptyElement(): bool
     /**
      * Convert this tPart to XML.
      *
-     * @param \DOMElement|null $parent The element we are converting to XML.
-     * @return \DOMElement The XML element after adding the data corresponding to this tPart.
+     * @param \Dom\Element|null $parent The element we are converting to XML.
+     * @return \Dom\Element The XML element after adding the data corresponding to this tPart.
      */
-    public function toXML(?DOMElement $parent = null): DOMElement
+    public function toXML(?Dom\Element $parent = null): Dom\Element
     {
         $e = parent::toXML($parent);
 
         $e->setAttribute('name', $this->getName()->getValue());
 
         if ($this->getElement() !== null) {
+            if (!$e->lookupPrefix($this->getElement()->getNamespacePrefix()->getValue())) {
+                $namespace = new XMLAttribute(
+                    C::NS_XMLNS,
+                    'xmlns',
+                    $this->getElement()->getNamespacePrefix()->getValue(),
+                    $this->getElement()->getNamespaceURI(),
+                );
+                $namespace->toXML($e);
+            }
+
             $e->setAttribute('element', $this->getElement()->getValue());
         }
 
         if ($this->getType() !== null) {
+            if (!$e->lookupPrefix($this->getType()->getNamespacePrefix()->getValue())) {
+                $namespace = new XMLAttribute(
+                    C::NS_XMLNS,
+                    'xmlns',
+                    $this->getType()->getNamespacePrefix()->getValue(),
+                    $this->getType()->getNamespaceURI(),
+                );
+                $namespace->toXML($e);
+            }
+
             $e->setAttribute('type', $this->getType()->getValue());
         }
 
diff --git a/src/XML/wsdl/AbstractPort.php b/src/XML/wsdl/AbstractPort.php
index 3f696b3..906a921 100644
--- a/src/XML/wsdl/AbstractPort.php
+++ b/src/XML/wsdl/AbstractPort.php
@@ -4,7 +4,9 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
+use SimpleSAML\XML\Attribute as XMLAttribute;
+use SimpleSAML\XML\Constants as C;
 use SimpleSAML\XMLSchema\Type\NCNameValue;
 use SimpleSAML\XMLSchema\Type\QNameValue;
 
@@ -66,14 +68,25 @@ public function isEmptyElement(): bool
     /**
      * Convert this tPort to XML.
      *
-     * @param \DOMElement|null $parent The element we are converting to XML.
-     * @return \DOMElement The XML element after adding the data corresponding to this tPort.
+     * @param \Dom\Element|null $parent The element we are converting to XML.
+     * @return \Dom\Element The XML element after adding the data corresponding to this tPort.
      */
-    public function toXML(?DOMElement $parent = null): DOMElement
+    public function toXML(?Dom\Element $parent = null): Dom\Element
     {
         $e = parent::toXML($parent);
 
         $e->setAttribute('name', $this->getName()->getValue());
+
+        if (!$e->lookupPrefix($this->getBinding()->getNamespacePrefix()->getValue())) {
+            $namespace = new XMLAttribute(
+                C::NS_XMLNS,
+                'xmlns',
+                $this->getBinding()->getNamespacePrefix()->getValue(),
+                $this->getBinding()->getNamespaceURI(),
+            );
+            $namespace->toXML($e);
+        }
+
         $e->setAttribute('binding', $this->getBinding()->getValue());
 
         return $e;
diff --git a/src/XML/wsdl/AbstractPortType.php b/src/XML/wsdl/AbstractPortType.php
index 99eaf80..4edfd57 100644
--- a/src/XML/wsdl/AbstractPortType.php
+++ b/src/XML/wsdl/AbstractPortType.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\WSDL\Assert\Assert;
 use SimpleSAML\XMLSchema\Exception\SchemaViolationException;
 use SimpleSAML\XMLSchema\Type\NCNameValue;
@@ -69,10 +69,10 @@ public function isEmptyElement(): bool
     /**
      * Convert this tPortType to XML.
      *
-     * @param \DOMElement|null $parent The element we are converting to XML.
-     * @return \DOMElement The XML element after adding the data corresponding to this tPortType.
+     * @param \Dom\Element|null $parent The element we are converting to XML.
+     * @return \Dom\Element The XML element after adding the data corresponding to this tPortType.
      */
-    public function toXML(?DOMElement $parent = null): DOMElement
+    public function toXML(?Dom\Element $parent = null): Dom\Element
     {
         $e = parent::toXML($parent);
 
diff --git a/src/XML/wsdl/AbstractPortTypeOperation.php b/src/XML/wsdl/AbstractPortTypeOperation.php
index 6cbcdb8..720df5e 100644
--- a/src/XML/wsdl/AbstractPortTypeOperation.php
+++ b/src/XML/wsdl/AbstractPortTypeOperation.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\WSDL\Assert\Assert;
 use SimpleSAML\XMLSchema\Exception\SchemaViolationException;
 use SimpleSAML\XMLSchema\Type\NCNameValue;
@@ -99,10 +99,10 @@ public function getFault(): array
     /**
      * Convert this RequestResponseOrOneWayOperation to XML.
      *
-     * @param \DOMElement|null $parent The element we should add this organization to.
-     * @return \DOMElement This Organization-element.
+     * @param \Dom\Element|null $parent The element we should add this organization to.
+     * @return \Dom\Element This Organization-element.
      */
-    public function toXML(?DOMElement $parent = null): DOMElement
+    public function toXML(?Dom\Element $parent = null): Dom\Element
     {
         $e = $this->instantiateParentElement($parent);
         $e->setAttribute('name', $this->getName()->getValue());
diff --git a/src/XML/wsdl/AbstractService.php b/src/XML/wsdl/AbstractService.php
index 851b0dd..aa405cb 100644
--- a/src/XML/wsdl/AbstractService.php
+++ b/src/XML/wsdl/AbstractService.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\WSDL\Assert\Assert;
 use SimpleSAML\XMLSchema\Exception\SchemaViolationException;
 use SimpleSAML\XMLSchema\Type\NCNameValue;
@@ -79,10 +79,10 @@ public function isEmptyElement(): bool
     /**
      * Convert this tService to XML.
      *
-     * @param \DOMElement|null $parent The element we are converting to XML.
-     * @return \DOMElement The XML element after adding the data corresponding to this tService.
+     * @param \Dom\Element|null $parent The element we are converting to XML.
+     * @return \Dom\Element The XML element after adding the data corresponding to this tService.
      */
-    public function toXML(?DOMElement $parent = null): DOMElement
+    public function toXML(?Dom\Element $parent = null): Dom\Element
     {
         $e = parent::toXML($parent);
 
diff --git a/src/XML/wsdl/Binding.php b/src/XML/wsdl/Binding.php
index 623d674..c6eb731 100644
--- a/src/XML/wsdl/Binding.php
+++ b/src/XML/wsdl/Binding.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\Assert\Assert;
 use SimpleSAML\XMLSchema\Exception\InvalidDOMElementException;
 use SimpleSAML\XMLSchema\Type\NCNameValue;
@@ -23,12 +23,12 @@ final class Binding extends AbstractBinding
     /**
      * Initialize a Binding element.
      *
-     * @param \DOMElement $xml The XML element we should load.
+     * @param \Dom\Element $xml The XML element we should load.
      *
      * @throws \SimpleSAML\XMLSchema\Exception\InvalidDOMElementException
      *   if the qualified name of the supplied element is wrong
      */
-    public static function fromXML(DOMElement $xml): static
+    public static function fromXML(Dom\Element $xml): static
     {
         Assert::same($xml->localName, static::LOCALNAME, InvalidDOMElementException::class);
         Assert::same($xml->namespaceURI, static::NS, InvalidDOMElementException::class);
diff --git a/src/XML/wsdl/BindingOperation.php b/src/XML/wsdl/BindingOperation.php
index 0316f84..6a1a137 100644
--- a/src/XML/wsdl/BindingOperation.php
+++ b/src/XML/wsdl/BindingOperation.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\Assert\Assert;
 use SimpleSAML\XMLSchema\Exception\InvalidDOMElementException;
 use SimpleSAML\XMLSchema\Type\NCNameValue;
@@ -24,12 +24,12 @@ final class BindingOperation extends AbstractBindingOperation
     /**
      * Initialize a BindingOperation element.
      *
-     * @param \DOMElement $xml The XML element we should load.
+     * @param \Dom\Element $xml The XML element we should load.
      *
      * @throws \SimpleSAML\XMLSchema\Exception\InvalidDOMElementException
      *   if the qualified name of the supplied element is wrong
      */
-    public static function fromXML(DOMElement $xml): static
+    public static function fromXML(Dom\Element $xml): static
     {
         Assert::same($xml->localName, static::LOCALNAME, InvalidDOMElementException::class);
         Assert::same($xml->namespaceURI, static::NS, InvalidDOMElementException::class);
diff --git a/src/XML/wsdl/BindingOperationFault.php b/src/XML/wsdl/BindingOperationFault.php
index 4b0ed94..db8c972 100644
--- a/src/XML/wsdl/BindingOperationFault.php
+++ b/src/XML/wsdl/BindingOperationFault.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\Assert\Assert;
 use SimpleSAML\XMLSchema\Exception\InvalidDOMElementException;
 use SimpleSAML\XMLSchema\Type\NCNameValue;
@@ -22,12 +22,12 @@ final class BindingOperationFault extends AbstractBindingOperationFault
     /**
      * Initialize a Fault element.
      *
-     * @param \DOMElement $xml The XML element we should load.
+     * @param \Dom\Element $xml The XML element we should load.
      *
      * @throws \SimpleSAML\XMLSchema\Exception\InvalidDOMElementException
      *   if the qualified name of the supplied element is wrong
      */
-    public static function fromXML(DOMElement $xml): static
+    public static function fromXML(Dom\Element $xml): static
     {
         Assert::same($xml->localName, static::LOCALNAME, InvalidDOMElementException::class);
         Assert::same($xml->namespaceURI, static::NS, InvalidDOMElementException::class);
diff --git a/src/XML/wsdl/BindingOperationInput.php b/src/XML/wsdl/BindingOperationInput.php
index 96b389a..d97a947 100644
--- a/src/XML/wsdl/BindingOperationInput.php
+++ b/src/XML/wsdl/BindingOperationInput.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\Assert\Assert;
 use SimpleSAML\XMLSchema\Exception\InvalidDOMElementException;
 use SimpleSAML\XMLSchema\Type\NCNameValue;
@@ -22,12 +22,12 @@ final class BindingOperationInput extends AbstractBindingOperationMessage
     /**
      * Initialize a Input element.
      *
-     * @param \DOMElement $xml The XML element we should load.
+     * @param \Dom\Element $xml The XML element we should load.
      *
      * @throws \SimpleSAML\XMLSchema\Exception\InvalidDOMElementException
      *   if the qualified name of the supplied element is wrong
      */
-    public static function fromXML(DOMElement $xml): static
+    public static function fromXML(Dom\Element $xml): static
     {
         Assert::same($xml->localName, static::LOCALNAME, InvalidDOMElementException::class);
         Assert::same($xml->namespaceURI, static::NS, InvalidDOMElementException::class);
diff --git a/src/XML/wsdl/BindingOperationOutput.php b/src/XML/wsdl/BindingOperationOutput.php
index 78a23c6..0ca18dd 100644
--- a/src/XML/wsdl/BindingOperationOutput.php
+++ b/src/XML/wsdl/BindingOperationOutput.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\Assert\Assert;
 use SimpleSAML\XMLSchema\Exception\InvalidDOMElementException;
 use SimpleSAML\XMLSchema\Type\NCNameValue;
@@ -22,12 +22,12 @@ final class BindingOperationOutput extends AbstractBindingOperationMessage
     /**
      * Initialize a Output element.
      *
-     * @param \DOMElement $xml The XML element we should load.
+     * @param \Dom\Element $xml The XML element we should load.
      *
      * @throws \SimpleSAML\XMLSchema\Exception\InvalidDOMElementException
      *   if the qualified name of the supplied element is wrong
      */
-    public static function fromXML(DOMElement $xml): static
+    public static function fromXML(Dom\Element $xml): static
     {
         Assert::same($xml->localName, static::LOCALNAME, InvalidDOMElementException::class);
         Assert::same($xml->namespaceURI, static::NS, InvalidDOMElementException::class);
diff --git a/src/XML/wsdl/Definitions.php b/src/XML/wsdl/Definitions.php
index 1dc7836..3e8f2e8 100644
--- a/src/XML/wsdl/Definitions.php
+++ b/src/XML/wsdl/Definitions.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\Assert\Assert;
 use SimpleSAML\XML\SchemaValidatableElementInterface;
 use SimpleSAML\XML\SchemaValidatableElementTrait;
@@ -33,12 +33,12 @@ final class Definitions extends AbstractDefinitions implements SchemaValidatable
     /**
      * Initialize a Definitions element.
      *
-     * @param \DOMElement $xml The XML element we should load.
+     * @param \Dom\Element $xml The XML element we should load.
      *
      * @throws \SimpleSAML\XMLSchema\Exception\InvalidDOMElementException
      *   if the qualified name of the supplied element is wrong
      */
-    public static function fromXML(DOMElement $xml): static
+    public static function fromXML(Dom\Element $xml): static
     {
         Assert::same($xml->localName, static::LOCALNAME, InvalidDOMElementException::class);
         Assert::same($xml->namespaceURI, static::NS, InvalidDOMElementException::class);
diff --git a/src/XML/wsdl/Fault.php b/src/XML/wsdl/Fault.php
index 2de0c10..483571a 100644
--- a/src/XML/wsdl/Fault.php
+++ b/src/XML/wsdl/Fault.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\Assert\Assert;
 use SimpleSAML\XMLSchema\Exception\InvalidDOMElementException;
 use SimpleSAML\XMLSchema\Type\NCNameValue;
@@ -23,12 +23,12 @@ final class Fault extends AbstractFault
     /**
      * Initialize a Fault element.
      *
-     * @param \DOMElement $xml The XML element we should load.
+     * @param \Dom\Element $xml The XML element we should load.
      *
      * @throws \SimpleSAML\XMLSchema\Exception\InvalidDOMElementException
      *   if the qualified name of the supplied element is wrong
      */
-    public static function fromXML(DOMElement $xml): static
+    public static function fromXML(Dom\Element $xml): static
     {
         Assert::same($xml->localName, static::LOCALNAME, InvalidDOMElementException::class);
         Assert::same($xml->namespaceURI, static::NS, InvalidDOMElementException::class);
diff --git a/src/XML/wsdl/Import.php b/src/XML/wsdl/Import.php
index 049e0c2..17d7a3b 100644
--- a/src/XML/wsdl/Import.php
+++ b/src/XML/wsdl/Import.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\Assert\Assert;
 use SimpleSAML\XMLSchema\Exception\InvalidDOMElementException;
 use SimpleSAML\XMLSchema\Type\AnyURIValue;
@@ -22,12 +22,12 @@ final class Import extends AbstractImport
     /**
      * Initialize a Import element.
      *
-     * @param \DOMElement $xml The XML element we should load.
+     * @param \Dom\Element $xml The XML element we should load.
      *
      * @throws \SimpleSAML\XMLSchema\Exception\InvalidDOMElementException
      *   if the qualified name of the supplied element is wrong
      */
-    public static function fromXML(DOMElement $xml): static
+    public static function fromXML(Dom\Element $xml): static
     {
         Assert::same($xml->localName, static::LOCALNAME, InvalidDOMElementException::class);
         Assert::same($xml->namespaceURI, static::NS, InvalidDOMElementException::class);
diff --git a/src/XML/wsdl/Input.php b/src/XML/wsdl/Input.php
index ffc41b0..d12ec76 100644
--- a/src/XML/wsdl/Input.php
+++ b/src/XML/wsdl/Input.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\Assert\Assert;
 use SimpleSAML\XMLSchema\Exception\InvalidDOMElementException;
 use SimpleSAML\XMLSchema\Type\NCNameValue;
@@ -23,12 +23,12 @@ final class Input extends AbstractParam
     /**
      * Initialize a input-element.
      *
-     * @param \DOMElement $xml The XML element we should load.
+     * @param \Dom\Element $xml The XML element we should load.
      *
      * @throws \SimpleSAML\XMLSchema\Exception\InvalidDOMElementException
      *   if the qualified name of the supplied element is wrong
      */
-    public static function fromXML(DOMElement $xml): static
+    public static function fromXML(Dom\Element $xml): static
     {
         Assert::same($xml->localName, static::LOCALNAME, InvalidDOMElementException::class);
         Assert::same($xml->namespaceURI, static::NS, InvalidDOMElementException::class);
diff --git a/src/XML/wsdl/Message.php b/src/XML/wsdl/Message.php
index 7811233..d9194af 100644
--- a/src/XML/wsdl/Message.php
+++ b/src/XML/wsdl/Message.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\Assert\Assert;
 use SimpleSAML\XMLSchema\Exception\InvalidDOMElementException;
 use SimpleSAML\XMLSchema\Type\NCNameValue;
@@ -22,12 +22,12 @@ final class Message extends AbstractMessage
     /**
      * Initialize a message-element.
      *
-     * @param \DOMElement $xml The XML element we should load.
+     * @param \Dom\Element $xml The XML element we should load.
      *
      * @throws \SimpleSAML\XMLSchema\Exception\InvalidDOMElementException
      *   if the qualified name of the supplied element is wrong
      */
-    public static function fromXML(DOMElement $xml): static
+    public static function fromXML(Dom\Element $xml): static
     {
         Assert::same($xml->localName, static::LOCALNAME, InvalidDOMElementException::class);
         Assert::same($xml->namespaceURI, static::NS, InvalidDOMElementException::class);
diff --git a/src/XML/wsdl/Output.php b/src/XML/wsdl/Output.php
index 4f4ca6e..6c26937 100644
--- a/src/XML/wsdl/Output.php
+++ b/src/XML/wsdl/Output.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\Assert\Assert;
 use SimpleSAML\XMLSchema\Exception\InvalidDOMElementException;
 use SimpleSAML\XMLSchema\Type\NCNameValue;
@@ -23,12 +23,12 @@ final class Output extends AbstractParam
     /**
      * Initialize a output-element.
      *
-     * @param \DOMElement $xml The XML element we should load.
+     * @param \Dom\Element $xml The XML element we should load.
      *
      * @throws \SimpleSAML\XMLSchema\Exception\InvalidDOMElementException
      *   if the qualified name of the supplied element is wrong
      */
-    public static function fromXML(DOMElement $xml): static
+    public static function fromXML(Dom\Element $xml): static
     {
         Assert::same($xml->localName, static::LOCALNAME, InvalidDOMElementException::class);
         Assert::same($xml->namespaceURI, static::NS, InvalidDOMElementException::class);
diff --git a/src/XML/wsdl/Part.php b/src/XML/wsdl/Part.php
index e2a5390..56de05f 100644
--- a/src/XML/wsdl/Part.php
+++ b/src/XML/wsdl/Part.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\Assert\Assert;
 use SimpleSAML\XMLSchema\Exception\InvalidDOMElementException;
 use SimpleSAML\XMLSchema\Type\NCNameValue;
@@ -23,12 +23,12 @@ final class Part extends AbstractPart
     /**
      * Initialize a Part element.
      *
-     * @param \DOMElement $xml The XML element we should load.
+     * @param \Dom\Element $xml The XML element we should load.
      *
      * @throws \SimpleSAML\XMLSchema\Exception\InvalidDOMElementException
      *   if the qualified name of the supplied element is wrong
      */
-    public static function fromXML(DOMElement $xml): static
+    public static function fromXML(Dom\Element $xml): static
     {
         Assert::same($xml->localName, static::LOCALNAME, InvalidDOMElementException::class);
         Assert::same($xml->namespaceURI, static::NS, InvalidDOMElementException::class);
diff --git a/src/XML/wsdl/Port.php b/src/XML/wsdl/Port.php
index 9000d64..a4611e4 100644
--- a/src/XML/wsdl/Port.php
+++ b/src/XML/wsdl/Port.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\Assert\Assert;
 use SimpleSAML\XMLSchema\Exception\InvalidDOMElementException;
 use SimpleSAML\XMLSchema\Type\NCNameValue;
@@ -23,12 +23,12 @@ final class Port extends AbstractPort
     /**
      * Initialize a Port element.
      *
-     * @param \DOMElement $xml The XML element we should load.
+     * @param \Dom\Element $xml The XML element we should load.
      *
      * @throws \SimpleSAML\XMLSchema\Exception\InvalidDOMElementException
      *   if the qualified name of the supplied element is wrong
      */
-    public static function fromXML(DOMElement $xml): static
+    public static function fromXML(Dom\Element $xml): static
     {
         Assert::same($xml->localName, static::LOCALNAME, InvalidDOMElementException::class);
         Assert::same($xml->namespaceURI, static::NS, InvalidDOMElementException::class);
diff --git a/src/XML/wsdl/PortType.php b/src/XML/wsdl/PortType.php
index 718bfe7..8aebf2b 100644
--- a/src/XML/wsdl/PortType.php
+++ b/src/XML/wsdl/PortType.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\Assert\Assert;
 use SimpleSAML\XMLSchema\Exception\InvalidDOMElementException;
 use SimpleSAML\XMLSchema\Type\NCNameValue;
@@ -22,12 +22,12 @@ final class PortType extends AbstractPortType
     /**
      * Initialize a PortType element.
      *
-     * @param \DOMElement $xml The XML element we should load.
+     * @param \Dom\Element $xml The XML element we should load.
      *
      * @throws \SimpleSAML\XMLSchema\Exception\InvalidDOMElementException
      *   if the qualified name of the supplied element is wrong
      */
-    public static function fromXML(DOMElement $xml): static
+    public static function fromXML(Dom\Element $xml): static
     {
         Assert::same($xml->localName, static::LOCALNAME, InvalidDOMElementException::class);
         Assert::same($xml->namespaceURI, static::NS, InvalidDOMElementException::class);
diff --git a/src/XML/wsdl/PortTypeOperation.php b/src/XML/wsdl/PortTypeOperation.php
index 41d877c..900b283 100644
--- a/src/XML/wsdl/PortTypeOperation.php
+++ b/src/XML/wsdl/PortTypeOperation.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\Assert\Assert;
 use SimpleSAML\XMLSchema\Exception\InvalidDOMElementException;
 use SimpleSAML\XMLSchema\Exception\SchemaViolationException;
@@ -24,19 +24,19 @@ final class PortTypeOperation extends AbstractPortTypeOperation
     /**
      * Initialize a Operation element.
      *
-     * @param \DOMElement $xml The XML element we should load.
+     * @param \Dom\Element $xml The XML element we should load.
      *
      * @throws \SimpleSAML\XMLSchema\Exception\InvalidDOMElementException
      *   if the qualified name of the supplied element is wrong
      */
-    public static function fromXML(DOMElement $xml): static
+    public static function fromXML(Dom\Element $xml): static
     {
         Assert::same($xml->localName, static::LOCALNAME, InvalidDOMElementException::class);
         Assert::same($xml->namespaceURI, static::NS, InvalidDOMElementException::class);
 
         $first = null;
         foreach ($xml->childNodes as $element) {
-            if (!($element instanceof DOMElement)) {
+            if (!($element instanceof Dom\Element)) {
                 continue;
             } elseif ($element->namespaceURI === static::NS) {
                 if ($element->localName === 'input') {
diff --git a/src/XML/wsdl/Service.php b/src/XML/wsdl/Service.php
index e8008a0..01f9895 100644
--- a/src/XML/wsdl/Service.php
+++ b/src/XML/wsdl/Service.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\Assert\Assert;
 use SimpleSAML\XMLSchema\Exception\InvalidDOMElementException;
 use SimpleSAML\XMLSchema\Type\NCNameValue;
@@ -22,12 +22,12 @@ final class Service extends AbstractService
     /**
      * Initialize a Service element.
      *
-     * @param \DOMElement $xml The XML element we should load.
+     * @param \Dom\Element $xml The XML element we should load.
      *
      * @throws \SimpleSAML\XMLSchema\Exception\InvalidDOMElementException
      *   if the qualified name of the supplied element is wrong
      */
-    public static function fromXML(DOMElement $xml): static
+    public static function fromXML(Dom\Element $xml): static
     {
         Assert::same($xml->localName, static::LOCALNAME, InvalidDOMElementException::class);
         Assert::same($xml->namespaceURI, static::NS, InvalidDOMElementException::class);
diff --git a/src/XML/wsdl/Types.php b/src/XML/wsdl/Types.php
index 820ab1c..5a32f41 100644
--- a/src/XML/wsdl/Types.php
+++ b/src/XML/wsdl/Types.php
@@ -4,7 +4,7 @@
 
 namespace SimpleSAML\WSDL\XML\wsdl;
 
-use DOMElement;
+use Dom;
 use SimpleSAML\Assert\Assert;
 use SimpleSAML\XMLSchema\Exception\InvalidDOMElementException;
 
@@ -21,12 +21,12 @@ final class Types extends AbstractTypes
     /**
      * Initialize a types-element.
      *
-     * @param \DOMElement $xml The XML element we should load.
+     * @param \Dom\Element $xml The XML element we should load.
      *
      * @throws \SimpleSAML\XMLSchema\Exception\InvalidDOMElementException
      *   if the qualified name of the supplied element is wrong
      */
-    public static function fromXML(DOMElement $xml): static
+    public static function fromXML(Dom\Element $xml): static
     {
         Assert::same($xml->localName, static::LOCALNAME, InvalidDOMElementException::class);
         Assert::same($xml->namespaceURI, static::NS, InvalidDOMElementException::class);
diff --git a/tests/WSDL/XML/soap12/AddressTest.php b/tests/WSDL/XML/soap12/AddressTest.php
index e623828..4a87fa5 100644
--- a/tests/WSDL/XML/soap12/AddressTest.php
+++ b/tests/WSDL/XML/soap12/AddressTest.php
@@ -61,9 +61,10 @@ public function testMarshalling(): void
             RequiredValue::fromBoolean(true),
         );
 
-        $this->assertEquals(
-            self::$xmlRepresentation->saveXML(self::$xmlRepresentation->documentElement),
-            strval($address),
-        );
+        $expectedXml = self::$xmlRepresentation->saveXml(self::$xmlRepresentation->documentElement);
+        $this->assertNotFalse($expectedXml);
+        $actualXml = strval($address);
+
+        $this->assertXmlStringEqualsXmlString($expectedXml, $actualXml);
     }
 }
diff --git a/tests/WSDL/XML/soap12/BindingTest.php b/tests/WSDL/XML/soap12/BindingTest.php
index cbe2d15..0406040 100644
--- a/tests/WSDL/XML/soap12/BindingTest.php
+++ b/tests/WSDL/XML/soap12/BindingTest.php
@@ -65,10 +65,11 @@ public function testMarshalling(): void
             RequiredValue::fromBoolean(true),
         );
 
-        $this->assertEquals(
-            self::$xmlRepresentation->saveXML(self::$xmlRepresentation->documentElement),
-            strval($binding),
-        );
+        $expectedXml = self::$xmlRepresentation->saveXml(self::$xmlRepresentation->documentElement);
+        $this->assertNotFalse($expectedXml);
+        $actualXml = strval($binding);
+
+        $this->assertXmlStringEqualsXmlString($expectedXml, $actualXml);
     }
 
 
diff --git a/tests/WSDL/XML/soap12/BodyTest.php b/tests/WSDL/XML/soap12/BodyTest.php
index 810567d..35f6e38 100644
--- a/tests/WSDL/XML/soap12/BodyTest.php
+++ b/tests/WSDL/XML/soap12/BodyTest.php
@@ -68,10 +68,11 @@ public function testMarshalling(): void
             RequiredValue::fromBoolean(true),
         );
 
-        $this->assertEquals(
-            self::$xmlRepresentation->saveXML(self::$xmlRepresentation->documentElement),
-            strval($body),
-        );
+        $expectedXml = self::$xmlRepresentation->saveXml(self::$xmlRepresentation->documentElement);
+        $this->assertNotFalse($expectedXml);
+        $actualXml = strval($body);
+
+        $this->assertXmlStringEqualsXmlString($expectedXml, $actualXml);
     }
 
 
diff --git a/tests/WSDL/XML/soap12/FaultTest.php b/tests/WSDL/XML/soap12/FaultTest.php
index ace9d8f..4136f4b 100644
--- a/tests/WSDL/XML/soap12/FaultTest.php
+++ b/tests/WSDL/XML/soap12/FaultTest.php
@@ -67,9 +67,10 @@ public function testMarshalling(): void
             RequiredValue::fromBoolean(true),
         );
 
-        $this->assertEquals(
-            self::$xmlRepresentation->saveXML(self::$xmlRepresentation->documentElement),
-            strval($fault),
-        );
+        $expectedXml = self::$xmlRepresentation->saveXml(self::$xmlRepresentation->documentElement);
+        $this->assertNotFalse($expectedXml);
+        $actualXml = strval($fault);
+
+        $this->assertXmlStringEqualsXmlString($expectedXml, $actualXml);
     }
 }
diff --git a/tests/WSDL/XML/soap12/HeaderFaultTest.php b/tests/WSDL/XML/soap12/HeaderFaultTest.php
index 8b0bea5..9df38b8 100644
--- a/tests/WSDL/XML/soap12/HeaderFaultTest.php
+++ b/tests/WSDL/XML/soap12/HeaderFaultTest.php
@@ -67,9 +67,10 @@ public function testMarshalling(): void
             AnyURIValue::fromString('urn:x-simplesamlphp:namespace'),
         );
 
-        $this->assertEquals(
-            self::$xmlRepresentation->saveXML(self::$xmlRepresentation->documentElement),
-            strval($headerFault),
-        );
+        $expectedXml = self::$xmlRepresentation->saveXml(self::$xmlRepresentation->documentElement);
+        $this->assertNotFalse($expectedXml);
+        $actualXml = strval($headerFault);
+
+        $this->assertXmlStringEqualsXmlString($expectedXml, $actualXml);
     }
 }
diff --git a/tests/WSDL/XML/soap12/HeaderTest.php b/tests/WSDL/XML/soap12/HeaderTest.php
index 1a8b4eb..5db1821 100644
--- a/tests/WSDL/XML/soap12/HeaderTest.php
+++ b/tests/WSDL/XML/soap12/HeaderTest.php
@@ -79,9 +79,10 @@ public function testMarshalling(): void
             RequiredValue::fromBoolean(true),
         );
 
-        $this->assertEquals(
-            self::$xmlRepresentation->saveXML(self::$xmlRepresentation->documentElement),
-            strval($header),
-        );
+        $expectedXml = self::$xmlRepresentation->saveXml(self::$xmlRepresentation->documentElement);
+        $this->assertNotFalse($expectedXml);
+        $actualXml = strval($header);
+
+        $this->assertXmlStringEqualsXmlString($expectedXml, $actualXml);
     }
 }
diff --git a/tests/WSDL/XML/soap12/OperationTest.php b/tests/WSDL/XML/soap12/OperationTest.php
index 400a325..77f65db 100644
--- a/tests/WSDL/XML/soap12/OperationTest.php
+++ b/tests/WSDL/XML/soap12/OperationTest.php
@@ -67,10 +67,11 @@ public function testMarshalling(): void
             RequiredValue::fromBoolean(true),
         );
 
-        $this->assertEquals(
-            self::$xmlRepresentation->saveXML(self::$xmlRepresentation->documentElement),
-            strval($operation),
-        );
+        $expectedXml = self::$xmlRepresentation->saveXml(self::$xmlRepresentation->documentElement);
+        $this->assertNotFalse($expectedXml);
+        $actualXml = strval($operation);
+
+        $this->assertXmlStringEqualsXmlString($expectedXml, $actualXml);
     }
 
 
diff --git a/tests/WSDL/XML/wsdl/BindingOperationTest.php b/tests/WSDL/XML/wsdl/BindingOperationTest.php
index c5e3516..407b635 100644
--- a/tests/WSDL/XML/wsdl/BindingOperationTest.php
+++ b/tests/WSDL/XML/wsdl/BindingOperationTest.php
@@ -100,9 +100,10 @@ public function testMarshalling(): void
             [new Chunk($child->documentElement)],
         );
 
-        $this->assertEquals(
-            self::$xmlRepresentation->saveXML(self::$xmlRepresentation->documentElement),
-            strval($bindingOperation),
-        );
+        $expectedXml = self::$xmlRepresentation->saveXml(self::$xmlRepresentation->documentElement);
+        $this->assertNotFalse($expectedXml);
+        $actualXml = strval($bindingOperation);
+
+        $this->assertXmlStringEqualsXmlString($expectedXml, $actualXml);
     }
 }
diff --git a/tests/WSDL/XML/wsdl/BindingTest.php b/tests/WSDL/XML/wsdl/BindingTest.php
index dad74e4..161d316 100644
--- a/tests/WSDL/XML/wsdl/BindingTest.php
+++ b/tests/WSDL/XML/wsdl/BindingTest.php
@@ -113,9 +113,10 @@ public function testMarshalling(): void
             [new Chunk($child->documentElement)],
         );
 
-        $this->assertEquals(
-            self::$xmlRepresentation->saveXML(self::$xmlRepresentation->documentElement),
-            strval($binding),
-        );
+        $expectedXml = self::$xmlRepresentation->saveXml(self::$xmlRepresentation->documentElement);
+        $this->assertNotFalse($expectedXml);
+        $actualXml = strval($binding);
+
+        $this->assertXmlStringEqualsXmlString($expectedXml, $actualXml);
     }
 }
diff --git a/tests/WSDL/XML/wsdl/DefinitionsTest.php b/tests/WSDL/XML/wsdl/DefinitionsTest.php
index 72b1d01..e7f16cd 100644
--- a/tests/WSDL/XML/wsdl/DefinitionsTest.php
+++ b/tests/WSDL/XML/wsdl/DefinitionsTest.php
@@ -70,6 +70,8 @@ public static function setUpBeforeClass(): void
         self::$xmlRepresentation = DOMDocumentFactory::fromFile(
             dirname(__FILE__, 4) . '/resources/xml/wsdl/Definitions.xml',
         );
+
+        self::$schemaFile = dirname(__FILE__, 4) . '/resources/schemas/simplesamlphp.xsd';
     }
 
 
@@ -248,9 +250,10 @@ public function testMarshalling(): void
             [new Chunk($child->documentElement)],
         );
 
-        $this->assertEquals(
-            self::$xmlRepresentation->saveXML(self::$xmlRepresentation->documentElement),
-            strval($definitions),
-        );
+        $expectedXml = self::$xmlRepresentation->saveXml(self::$xmlRepresentation->documentElement);
+        $this->assertNotFalse($expectedXml);
+        $actualXml = strval($definitions);
+
+        $this->assertXmlStringEqualsXmlString($expectedXml, $actualXml);
     }
 }
diff --git a/tests/WSDL/XML/wsdl/FaultTest.php b/tests/WSDL/XML/wsdl/FaultTest.php
index f32b2f2..60b58c6 100644
--- a/tests/WSDL/XML/wsdl/FaultTest.php
+++ b/tests/WSDL/XML/wsdl/FaultTest.php
@@ -64,9 +64,10 @@ public function testMarshalling(): void
             [$attr1],
         );
 
-        $this->assertEquals(
-            self::$xmlRepresentation->saveXML(self::$xmlRepresentation->documentElement),
-            strval($fault),
-        );
+        $expectedXml = self::$xmlRepresentation->saveXml(self::$xmlRepresentation->documentElement);
+        $this->assertNotFalse($expectedXml);
+        $actualXml = strval($fault);
+
+        $this->assertXmlStringEqualsXmlString($expectedXml, $actualXml);
     }
 }
diff --git a/tests/WSDL/XML/wsdl/ImportTest.php b/tests/WSDL/XML/wsdl/ImportTest.php
index e7bef14..debb2c4 100644
--- a/tests/WSDL/XML/wsdl/ImportTest.php
+++ b/tests/WSDL/XML/wsdl/ImportTest.php
@@ -63,9 +63,10 @@ public function testMarshalling(): void
             [$attr1],
         );
 
-        $this->assertEquals(
-            self::$xmlRepresentation->saveXML(self::$xmlRepresentation->documentElement),
-            strval($import),
-        );
+        $expectedXml = self::$xmlRepresentation->saveXml(self::$xmlRepresentation->documentElement);
+        $this->assertNotFalse($expectedXml);
+        $actualXml = strval($import);
+
+        $this->assertXmlStringEqualsXmlString($expectedXml, $actualXml);
     }
 }
diff --git a/tests/WSDL/XML/wsdl/InputTest.php b/tests/WSDL/XML/wsdl/InputTest.php
index 734576d..1726ac9 100644
--- a/tests/WSDL/XML/wsdl/InputTest.php
+++ b/tests/WSDL/XML/wsdl/InputTest.php
@@ -66,9 +66,10 @@ public function testMarshalling(): void
             [$attr1],
         );
 
-        $this->assertEquals(
-            self::$xmlRepresentation->saveXML(self::$xmlRepresentation->documentElement),
-            strval($input),
-        );
+        $expectedXml = self::$xmlRepresentation->saveXml(self::$xmlRepresentation->documentElement);
+        $this->assertNotFalse($expectedXml);
+        $actualXml = strval($input);
+
+        $this->assertXmlStringEqualsXmlString($expectedXml, $actualXml);
     }
 }
diff --git a/tests/WSDL/XML/wsdl/MessageTest.php b/tests/WSDL/XML/wsdl/MessageTest.php
index 8bca35f..5313569 100644
--- a/tests/WSDL/XML/wsdl/MessageTest.php
+++ b/tests/WSDL/XML/wsdl/MessageTest.php
@@ -86,10 +86,11 @@ public function testMarshalling(): void
             [new Chunk($child->documentElement)],
         );
 
-        $this->assertEquals(
-            self::$xmlRepresentation->saveXML(self::$xmlRepresentation->documentElement),
-            strval($message),
-        );
+        $expectedXml = self::$xmlRepresentation->saveXml(self::$xmlRepresentation->documentElement);
+        $this->assertNotFalse($expectedXml);
+        $actualXml = strval($message);
+
+        $this->assertXmlStringEqualsXmlString($expectedXml, $actualXml);
     }
 
 
diff --git a/tests/WSDL/XML/wsdl/OutputTest.php b/tests/WSDL/XML/wsdl/OutputTest.php
index 1c6b4ff..efcd285 100644
--- a/tests/WSDL/XML/wsdl/OutputTest.php
+++ b/tests/WSDL/XML/wsdl/OutputTest.php
@@ -66,9 +66,10 @@ public function testMarshalling(): void
             [$attr1],
         );
 
-        $this->assertEquals(
-            self::$xmlRepresentation->saveXML(self::$xmlRepresentation->documentElement),
-            strval($output),
-        );
+        $expectedXml = self::$xmlRepresentation->saveXml(self::$xmlRepresentation->documentElement);
+        $this->assertNotFalse($expectedXml);
+        $actualXml = strval($output);
+
+        $this->assertXmlStringEqualsXmlString($expectedXml, $actualXml);
     }
 }
diff --git a/tests/WSDL/XML/wsdl/PartTest.php b/tests/WSDL/XML/wsdl/PartTest.php
index 0b23760..5bd4817 100644
--- a/tests/WSDL/XML/wsdl/PartTest.php
+++ b/tests/WSDL/XML/wsdl/PartTest.php
@@ -65,9 +65,10 @@ public function testMarshalling(): void
             [$attr1],
         );
 
-        $this->assertEquals(
-            self::$xmlRepresentation->saveXML(self::$xmlRepresentation->documentElement),
-            strval($part),
-        );
+        $expectedXml = self::$xmlRepresentation->saveXml(self::$xmlRepresentation->documentElement);
+        $this->assertNotFalse($expectedXml);
+        $actualXml = strval($part);
+
+        $this->assertXmlStringEqualsXmlString($expectedXml, $actualXml);
     }
 }
diff --git a/tests/WSDL/XML/wsdl/PortTest.php b/tests/WSDL/XML/wsdl/PortTest.php
index 902515b..c4b9404 100644
--- a/tests/WSDL/XML/wsdl/PortTest.php
+++ b/tests/WSDL/XML/wsdl/PortTest.php
@@ -65,9 +65,10 @@ public function testMarshalling(): void
             [new Chunk($child->documentElement)],
         );
 
-        $this->assertEquals(
-            self::$xmlRepresentation->saveXML(self::$xmlRepresentation->documentElement),
-            strval($port),
-        );
+        $expectedXml = self::$xmlRepresentation->saveXml(self::$xmlRepresentation->documentElement);
+        $this->assertNotFalse($expectedXml);
+        $actualXml = strval($port);
+
+        $this->assertXmlStringEqualsXmlString($expectedXml, $actualXml);
     }
 }
diff --git a/tests/WSDL/XML/wsdl/PortTypeOperationInputTest.php b/tests/WSDL/XML/wsdl/PortTypeOperationInputTest.php
index 93d9341..12fb491 100644
--- a/tests/WSDL/XML/wsdl/PortTypeOperationInputTest.php
+++ b/tests/WSDL/XML/wsdl/PortTypeOperationInputTest.php
@@ -93,9 +93,10 @@ public function testMarshalling(): void
             [$fault],
         );
 
-        $this->assertEquals(
-            self::$xmlRepresentation->saveXML(self::$xmlRepresentation->documentElement),
-            strval($operation),
-        );
+        $expectedXml = self::$xmlRepresentation->saveXml(self::$xmlRepresentation->documentElement);
+        $this->assertNotFalse($expectedXml);
+        $actualXml = strval($operation);
+
+        $this->assertXmlStringEqualsXmlString($expectedXml, $actualXml);
     }
 }
diff --git a/tests/WSDL/XML/wsdl/PortTypeOperationOutputTest.php b/tests/WSDL/XML/wsdl/PortTypeOperationOutputTest.php
index 708cc0f..d9ab365 100644
--- a/tests/WSDL/XML/wsdl/PortTypeOperationOutputTest.php
+++ b/tests/WSDL/XML/wsdl/PortTypeOperationOutputTest.php
@@ -93,9 +93,10 @@ public function testMarshalling(): void
             [$fault],
         );
 
-        $this->assertEquals(
-            self::$xmlRepresentation->saveXML(self::$xmlRepresentation->documentElement),
-            strval($operation),
-        );
+        $expectedXml = self::$xmlRepresentation->saveXml(self::$xmlRepresentation->documentElement);
+        $this->assertNotFalse($expectedXml);
+        $actualXml = strval($operation);
+
+        $this->assertXmlStringEqualsXmlString($expectedXml, $actualXml);
     }
 }
diff --git a/tests/WSDL/XML/wsdl/PortTypeTest.php b/tests/WSDL/XML/wsdl/PortTypeTest.php
index 13a61d5..ff4ae23 100644
--- a/tests/WSDL/XML/wsdl/PortTypeTest.php
+++ b/tests/WSDL/XML/wsdl/PortTypeTest.php
@@ -103,9 +103,10 @@ public function testMarshalling(): void
 
         $portType = new PortType(NCNameValue::fromString('MyPort'), [$inputOperation, $outputOperation], [$port]);
 
-        $this->assertEquals(
-            self::$xmlRepresentation->saveXML(self::$xmlRepresentation->documentElement),
-            strval($portType),
-        );
+        $expectedXml = self::$xmlRepresentation->saveXml(self::$xmlRepresentation->documentElement);
+        $this->assertNotFalse($expectedXml);
+        $actualXml = strval($portType);
+
+        $this->assertXmlStringEqualsXmlString($expectedXml, $actualXml);
     }
 }
diff --git a/tests/WSDL/XML/wsdl/ServiceTest.php b/tests/WSDL/XML/wsdl/ServiceTest.php
index 2c6bd4b..3dfd5c7 100644
--- a/tests/WSDL/XML/wsdl/ServiceTest.php
+++ b/tests/WSDL/XML/wsdl/ServiceTest.php
@@ -82,10 +82,11 @@ public function testMarshalling(): void
             [$portOne, $portTwo],
             [new Chunk($child->documentElement)],
         );
-//var_dump(strval($service));
-        $this->assertEquals(
-            self::$xmlRepresentation->saveXML(self::$xmlRepresentation->documentElement),
-            strval($service),
-        );
+
+        $expectedXml = self::$xmlRepresentation->saveXml(self::$xmlRepresentation->documentElement);
+        $this->assertNotFalse($expectedXml);
+        $actualXml = strval($service);
+
+        $this->assertXmlStringEqualsXmlString($expectedXml, $actualXml);
     }
 }
diff --git a/tests/WSDL/XML/wsdl/TypesTest.php b/tests/WSDL/XML/wsdl/TypesTest.php
index 04c5083..088c0a1 100644
--- a/tests/WSDL/XML/wsdl/TypesTest.php
+++ b/tests/WSDL/XML/wsdl/TypesTest.php
@@ -59,9 +59,10 @@ public function testMarshalling(): void
 
         $types = new Types([new Chunk($child->documentElement)]);
 
-        $this->assertEquals(
-            self::$xmlRepresentation->saveXML(self::$xmlRepresentation->documentElement),
-            strval($types),
-        );
+        $expectedXml = self::$xmlRepresentation->saveXml(self::$xmlRepresentation->documentElement);
+        $this->assertNotFalse($expectedXml);
+        $actualXml = strval($types);
+
+        $this->assertXmlStringEqualsXmlString($expectedXml, $actualXml);
     }
 }
diff --git a/tests/resources/schemas/simplesamlphp.xsd b/tests/resources/schemas/simplesamlphp.xsd
new file mode 100644
index 0000000..10542b8
--- /dev/null
+++ b/tests/resources/schemas/simplesamlphp.xsd
@@ -0,0 +1,45 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!-- Schema for SimpleSAMLphp dummy classes -->
+
+<schema xmlns="http://www.w3.org/2001/XMLSchema"
+        xmlns:ssp="urn:x-simplesamlphp:namespace"
+        xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/"
+        targetNamespace="urn:x-simplesamlphp:namespace"
+        version="0.1" elementFormDefault="qualified" attributeFormDefault="qualified"> 
+
+<import namespace='http://schemas.xmlsoap.org/wsdl/'
+          schemaLocation='../../../resources/schemas/wsdl.xsd'/>
+
+<!-- Start CustomElement -->
+
+<element name="CustomElement" type="string"/>
+
+<!-- End CustomElement -->
+
+<!-- Start CustomInputMessage -->
+
+<element name="CustomInputMessage" type="string"/>
+
+<!-- End CustomInputMessage -->
+
+<!-- Start CustomOutputMessage -->
+
+<element name="CustomOutputMessage" type="string"/>
+
+<!-- End CustomOutputMessage -->
+
+<!-- Start CustomFaultMessage -->
+
+<element name="CustomFaultMessage" type="string"/>
+
+<!-- End CustomFaultMessage -->
+
+<!-- Start Chunk -->
+
+<element name="Chunk" type="string"/>
+
+<!-- End Chunk -->
+
+</schema>
+
diff --git a/tests/resources/xml/wsdl/PortTypeOperation_Input.xml b/tests/resources/xml/wsdl/PortTypeOperation_Input.xml
index dba2608..40e29eb 100644
--- a/tests/resources/xml/wsdl/PortTypeOperation_Input.xml
+++ b/tests/resources/xml/wsdl/PortTypeOperation_Input.xml
@@ -1,5 +1,5 @@
-<wsdl:operation xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" xmlns:ssp="urn:x-simplesamlphp:namespace" name="CustomName" parameterOrder="0836217462 0836217463">
-  <wsdl:input ssp:attr1="value1" name="CustomInputName" message="ssp:CustomInputMessage"/>
-  <wsdl:output ssp:attr2="value2" name="CustomOutputName" message="ssp:CustomOutputMessage"/>
-  <wsdl:fault ssp:attr3="value3" name="CustomFaultName" message="ssp:CustomFaultMessage"/>
+<wsdl:operation xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" name="CustomName" parameterOrder="0836217462 0836217463">
+  <wsdl:input xmlns:ssp="urn:x-simplesamlphp:namespace" ssp:attr1="value1" name="CustomInputName" message="ssp:CustomInputMessage"/>
+  <wsdl:output xmlns:ssp="urn:x-simplesamlphp:namespace" ssp:attr2="value2" name="CustomOutputName" message="ssp:CustomOutputMessage"/>
+  <wsdl:fault xmlns:ssp="urn:x-simplesamlphp:namespace" ssp:attr3="value3" name="CustomFaultName" message="ssp:CustomFaultMessage"/>
 </wsdl:operation>
diff --git a/tests/resources/xml/wsdl/PortTypeOperation_Output.xml b/tests/resources/xml/wsdl/PortTypeOperation_Output.xml
index 651b1f5..058211d 100644
--- a/tests/resources/xml/wsdl/PortTypeOperation_Output.xml
+++ b/tests/resources/xml/wsdl/PortTypeOperation_Output.xml
@@ -1,5 +1,5 @@
-<wsdl:operation xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" xmlns:ssp="urn:x-simplesamlphp:namespace" name="CustomName" parameterOrder="0836217462 0836217463">
-  <wsdl:output ssp:attr1="value1" name="CustomOutputName" message="ssp:CustomOutputMessage"/>
-  <wsdl:input ssp:attr2="value2" name="CustomInputName" message="ssp:CustomInputMessage"/>
-  <wsdl:fault ssp:attr3="value3" name="CustomFaultName" message="ssp:CustomFaultMessage"/>
+<wsdl:operation xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" name="CustomName" parameterOrder="0836217462 0836217463">
+  <wsdl:output xmlns:ssp="urn:x-simplesamlphp:namespace" ssp:attr1="value1" name="CustomOutputName" message="ssp:CustomOutputMessage"/>
+  <wsdl:input xmlns:ssp="urn:x-simplesamlphp:namespace" ssp:attr2="value2" name="CustomInputName" message="ssp:CustomInputMessage"/>
+  <wsdl:fault xmlns:ssp="urn:x-simplesamlphp:namespace" ssp:attr3="value3" name="CustomFaultName" message="ssp:CustomFaultMessage"/>
 </wsdl:operation>