diff --git a/core-api/src/main/java/com/optimizely/ab/config/parser/GsonConfigParser.java b/core-api/src/main/java/com/optimizely/ab/config/parser/GsonConfigParser.java
index 314f2dd23..61af8e6f2 100644
--- a/core-api/src/main/java/com/optimizely/ab/config/parser/GsonConfigParser.java
+++ b/core-api/src/main/java/com/optimizely/ab/config/parser/GsonConfigParser.java
@@ -20,6 +20,7 @@
 
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
+import com.google.gson.ToNumberPolicy;
 import com.optimizely.ab.config.DatafileProjectConfig;
 import com.optimizely.ab.config.Experiment;
 import com.optimizely.ab.config.FeatureFlag;
@@ -37,6 +38,7 @@ final public class GsonConfigParser implements ConfigParser {
 
     public GsonConfigParser() {
         this(new GsonBuilder()
+            .setObjectToNumberStrategy(ToNumberPolicy.LONG_OR_DOUBLE)
             .registerTypeAdapter(Audience.class, new AudienceGsonDeserializer())
             .registerTypeAdapter(TypedAudience.class, new AudienceGsonDeserializer())
             .registerTypeAdapter(Experiment.class, new ExperimentGsonDeserializer())
diff --git a/core-api/src/test/java/com/optimizely/ab/config/parser/GsonConfigParserTest.java b/core-api/src/test/java/com/optimizely/ab/config/parser/GsonConfigParserTest.java
index ec02aaad0..5e1dca11c 100644
--- a/core-api/src/test/java/com/optimizely/ab/config/parser/GsonConfigParserTest.java
+++ b/core-api/src/test/java/com/optimizely/ab/config/parser/GsonConfigParserTest.java
@@ -404,19 +404,20 @@ public void testToJson() {
 
     @Test
     public void testFromJson() {
-        String json = "{\"k1\":\"v1\",\"k2\":3.5,\"k3\":true}";
+        String json = "{\"k1\":\"v1\",\"k2\":3.5,\"k3\":true,\"k4\":12345}";
 
         Map<String, Object> expectedMap = new HashMap<>();
         expectedMap.put("k1", "v1");
         expectedMap.put("k2", 3.5);
         expectedMap.put("k3", true);
+        expectedMap.put("k4", 12345L);
 
         GsonConfigParser parser = new GsonConfigParser();
 
-        Map map = null;
+        Map<String, Object> map = null;
         try {
             map = parser.fromJson(json, Map.class);
-            assertEquals(map, expectedMap);
+            assertEquals(expectedMap, map);
         } catch (JsonParseException e) {
             fail("Parse to map failed: " + e.getMessage());
         }
diff --git a/core-api/src/test/java/com/optimizely/ab/optimizelyjson/OptimizelyJSONWithGsonParserTest.java b/core-api/src/test/java/com/optimizely/ab/optimizelyjson/OptimizelyJSONWithGsonParserTest.java
index ebbed4bf5..5cc7246bc 100644
--- a/core-api/src/test/java/com/optimizely/ab/optimizelyjson/OptimizelyJSONWithGsonParserTest.java
+++ b/core-api/src/test/java/com/optimizely/ab/optimizelyjson/OptimizelyJSONWithGsonParserTest.java
@@ -50,16 +50,16 @@ public void testGetValueWithNotMatchingType() throws JsonParseException {
     @Test
     public void testIntegerProcessing() throws JsonParseException {
 
-        // GSON parser toMap() adds ".0" to all integers
+        // GSON parser toMap() converts integers to longs
 
         String json = "{\"k1\":1,\"k2\":2.5,\"k3\":{\"kk1\":3,\"kk2\":4.0}}";
 
         Map<String,Object> m2 = new HashMap<String,Object>();
-        m2.put("kk1", 3.0);
+        m2.put("kk1", 3L);
         m2.put("kk2", 4.0);
 
         Map<String,Object> m1 = new HashMap<String,Object>();
-        m1.put("k1", 1.0);
+        m1.put("k1", 1L);
         m1.put("k2", 2.5);
         m1.put("k3", m2);