diff --git a/src/generators/csharp/presets/JsonSerializerPreset.ts b/src/generators/csharp/presets/JsonSerializerPreset.ts
index eefd5fd1df..2299cfbec0 100644
--- a/src/generators/csharp/presets/JsonSerializerPreset.ts
+++ b/src/generators/csharp/presets/JsonSerializerPreset.ts
@@ -20,7 +20,7 @@ function renderSerializeProperty(
     model.property instanceof ConstrainedReferenceModel &&
     model.property.ref instanceof ConstrainedEnumModel
   ) {
-    value = `value.${model.property.type}.GetValue()`;
+    value = `${modelInstanceVariable}?.GetValue()`;
   }
   return `JsonSerializer.Serialize(writer, ${value}, options);`;
 }
diff --git a/test/generators/csharp/presets/__snapshots__/JsonSerializerPreset.spec.ts.snap b/test/generators/csharp/presets/__snapshots__/JsonSerializerPreset.spec.ts.snap
index 6d60375705..21ac576590 100644
--- a/test/generators/csharp/presets/__snapshots__/JsonSerializerPreset.spec.ts.snap
+++ b/test/generators/csharp/presets/__snapshots__/JsonSerializerPreset.spec.ts.snap
@@ -127,7 +127,7 @@ internal class TestConverter : JsonConverter<Test>
     if(value.EnumProp != null) {
       // write property name and let the serializer serialize the value itself
       writer.WritePropertyName(\\"enumProp\\");
-      JsonSerializer.Serialize(writer, value.EnumTest?.GetValue(), options);
+      JsonSerializer.Serialize(writer, value.EnumProp?.GetValue(), options);
     }
     if(value.ObjectProp != null) {
       // write property name and let the serializer serialize the value itself
diff --git a/test/runtime/generic-input.json b/test/runtime/generic-input.json
index afe3656468..9ecb63c338 100644
--- a/test/runtime/generic-input.json
+++ b/test/runtime/generic-input.json
@@ -47,6 +47,13 @@
     },
     "enumTest": {
       "enum": ["test", "test2"]
+    },
+    "houseType": {
+      "$ref": "#/$defs/housing-types"
+    },
+    "roofType": {
+      "$id": "TypeOfRoof",
+      "enum": ["tile", "straw", "wood", "metal"]
     }
   },
   "patternProperties": {
@@ -57,5 +64,11 @@
   "required": [
     "house_number",
     "array_type"
-  ]
+  ],
+  "$defs": {
+    "housing-types": {
+      "$id": "HousingType",
+      "enum": ["detached", "terraced", "bungalow", "flat"]
+    }
+  }
 }
\ No newline at end of file
diff --git a/test/runtime/runtime-csharp/runtime-csharp/test/models/json_serializer/Address.cs b/test/runtime/runtime-csharp/runtime-csharp/test/models/json_serializer/Address.cs
index bb50cce423..de0f6ab5e0 100644
--- a/test/runtime/runtime-csharp/runtime-csharp/test/models/json_serializer/Address.cs
+++ b/test/runtime/runtime-csharp/runtime-csharp/test/models/json_serializer/Address.cs
@@ -1,5 +1,5 @@
-using System.Text.Json;
-using com.mycompany.app.json_serializer;
+using com.mycompany.app.json_serializer;
+using System.Text.Json;
 
 namespace runtime_csharp.json_serializer;
 
@@ -14,8 +14,8 @@ public void Setup()
     [Test]
     public void TestSerializingFullModel()
     {
-        Address address = new Address();
-        NestedObject nestedObject = new NestedObject();
+        Address address = new();
+        NestedObject nestedObject = new();
         nestedObject.Test = "test";
         address.NestedObject = nestedObject;
         address.Marriage = true;
@@ -23,11 +23,13 @@ public void TestSerializingFullModel()
         address.HouseNumber = 1;
         address.ArrayType = new dynamic[] { 1, "test" };
         address.EnumTest = EnumTest.TEST;
+        address.HouseType = HousingType.FLAT;
+        address.RoofType = TypeOfRoof.STRAW;
         address.AdditionalProperties = new Dictionary<string, dynamic>();
         address.AdditionalProperties.Add("test_not_used", 2);
 
         string actualJsonString = JsonSerializer.Serialize(address);
-        string expectedJsonString = "{\"house_number\":1,\"marriage\":true,\"members\":2,\"array_type\":[1,\"test\"],\"nestedObject\":{\"test\":\"test\"},\"enumTest\":\"test\",\"test_not_used\":2}";
+        string expectedJsonString = "{\"house_number\":1,\"marriage\":true,\"members\":2,\"array_type\":[1,\"test\"],\"nestedObject\":{\"test\":\"test\"},\"enumTest\":\"test\",\"houseType\":\"flat\",\"roofType\":\"straw\",\"test_not_used\":2}";
         Assert.That(actualJsonString, Is.EqualTo(expectedJsonString));
     }
 }
diff --git a/test/runtime/runtime-csharp/runtime-csharp/test/models/newtonsoft/Address.cs b/test/runtime/runtime-csharp/runtime-csharp/test/models/newtonsoft/Address.cs
index 896823abbb..9fb5b3c686 100644
--- a/test/runtime/runtime-csharp/runtime-csharp/test/models/newtonsoft/Address.cs
+++ b/test/runtime/runtime-csharp/runtime-csharp/test/models/newtonsoft/Address.cs
@@ -1,5 +1,4 @@
-using System.Text.Json;
-using com.mycompany.app.newtonsoft;
+using com.mycompany.app.newtonsoft;
 using Newtonsoft.Json;
 
 namespace runtime_csharp.newtonsoft;
@@ -15,8 +14,8 @@ public void Setup()
     [Test]
     public void TestSerializingFullModel()
     {
-        Address address = new Address();
-        NestedObject nestedObject = new NestedObject();
+        Address address = new();
+        NestedObject nestedObject = new();
         nestedObject.Test = "test";
         address.NestedObject = nestedObject;
         address.Marriage = true;
@@ -24,11 +23,13 @@ public void TestSerializingFullModel()
         address.HouseNumber = 1;
         address.ArrayType = new dynamic[] { 1, "test" };
         address.EnumTest = EnumTest.TEST;
+        address.HouseType = HousingType.FLAT;
+        address.RoofType = TypeOfRoof.STRAW;
         address.AdditionalProperties = new Dictionary<string, dynamic>();
         address.AdditionalProperties.Add("test_not_used", 2);
 
         string actualJsonString = JsonConvert.SerializeObject(address);
-        string expectedJsonString = "{\"house_number\":1.0,\"marriage\":true,\"members\":2,\"array_type\":[1,\"test\"],\"nestedObject\":{\"test\":\"test\"},\"enumTest\":\"test\",\"test_not_used\":2}";
+        string expectedJsonString = "{\"house_number\":1.0,\"marriage\":true,\"members\":2,\"array_type\":[1,\"test\"],\"nestedObject\":{\"test\":\"test\"},\"enumTest\":\"test\",\"houseType\":\"flat\",\"roofType\":\"straw\",\"test_not_used\":2}";
         Assert.That(actualJsonString, Is.EqualTo(expectedJsonString));
     }
 }