diff --git a/src/Differ.php b/src/Differ.php
index f03206e..956bdea 100644
--- a/src/Differ.php
+++ b/src/Differ.php
@@ -483,7 +483,7 @@ private function finalize(): self
 
             $this->oldNoEolAtEofIdx = $this->getOld(-1) === [''] ? -1 : \count($this->old);
             $this->newNoEolAtEofIdx = $this->getNew(-1) === [''] ? -1 : \count($this->new);
-            $this->oldNewComparison = $this->old <=> $this->new;
+            $this->oldNewComparison = $this->old === $this->new ? 0 : ($this->old <=> $this->new ?: 1);
 
             $this->sequenceMatcher->setOptions($this->options->toSequenceMatcherOptions());
         }
diff --git a/tests/DifferTest.php b/tests/DifferTest.php
index 985e201..4d1c46a 100644
--- a/tests/DifferTest.php
+++ b/tests/DifferTest.php
@@ -18,6 +18,19 @@
  */
 final class DifferTest extends TestCase
 {
+    /**
+     * Test that numeric strings that are equal numerically but not identical
+     * (e.g. "00" vs "0") are correctly detected as different.
+     *
+     * @covers \Jfcherng\Diff\Differ::getOldNewComparison
+     */
+    public function testNumericStringComparisonIsStrict(): void
+    {
+        $differ = new Differ(['00'], ['0']);
+
+        self::assertNotSame(0, $differ->getOldNewComparison());
+    }
+
     /**
      * Test the Differ::getGroupedOpcodes.
      *