diff --git a/CHANGELOG.md b/CHANGELOG.md
index 23ea913175..d02c06c805 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
+- Fixed an issue where when generating Go code the deserializer for unions was using `CodeClass` as a filter and not `CodeInterface`. [#4844](https://github.com/microsoft/kiota/issues/4844)
 - Fixes mapping of `int16` format to the `integer` type rather than `double` when the type is `integer` or `number` [#5611](https://github.com/microsoft/kiota/issues/5611)
 
 ## [1.19.1] - 2024-10-11
diff --git a/src/Kiota.Builder/Writers/Go/CodeMethodWriter.cs b/src/Kiota.Builder/Writers/Go/CodeMethodWriter.cs
index 8a50297c80..59a288062b 100644
--- a/src/Kiota.Builder/Writers/Go/CodeMethodWriter.cs
+++ b/src/Kiota.Builder/Writers/Go/CodeMethodWriter.cs
@@ -632,7 +632,7 @@ private static void WriteDeserializerBodyForUnionModel(CodeMethod method, CodeCl
         var otherPropGetters = parentClass
                                 .GetPropertiesOfKind(CodePropertyKind.Custom)
                                 .Where(static x => !x.ExistsInBaseType && x.Getter != null)
-                                .Where(static x => x.Type is CodeType propertyType && !propertyType.IsCollection && propertyType.TypeDefinition is CodeClass)
+                                .Where(static x => x.Type is CodeType propertyType && !propertyType.IsCollection && propertyType.TypeDefinition is CodeInterface)
                                 .OrderBy(static x => x, CodePropertyTypeForwardComparer)
                                 .ThenBy(static x => x.Name)
                                 .Select(static x => x.Getter!.Name.ToFirstCharacterUpperCase())
diff --git a/tests/Kiota.Builder.Tests/Writers/Go/CodeMethodWriterTests.cs b/tests/Kiota.Builder.Tests/Writers/Go/CodeMethodWriterTests.cs
index 771c815782..885af77aae 100644
--- a/tests/Kiota.Builder.Tests/Writers/Go/CodeMethodWriterTests.cs
+++ b/tests/Kiota.Builder.Tests/Writers/Go/CodeMethodWriterTests.cs
@@ -291,16 +291,20 @@ private void AddSerializationBackingStoreMethods()
     }
     private CodeClass AddUnionTypeWrapper()
     {
-        var complexType1 = root.AddClass(new CodeClass
+        var complexType1 = root.AddInterface(new CodeInterface
         {
             Name = "ComplexType1",
-            Kind = CodeClassKind.Model,
+            Kind = CodeInterfaceKind.Model,
+            OriginalClass = new CodeClass { Name = "ComplexType1", Kind = CodeClassKind.Model }
         }).First();
-        var complexType2 = root.AddClass(new CodeClass
+
+        var complexType2 = root.AddInterface(new CodeInterface
         {
             Name = "ComplexType2",
-            Kind = CodeClassKind.Model,
+            Kind = CodeInterfaceKind.Model,
+            OriginalClass = new CodeClass { Name = "ComplexType2", Kind = CodeClassKind.Model }
         }).First();
+
         var unionTypeWrapper = root.AddClass(new CodeClass
         {
             Name = "UnionTypeWrapper",