diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools.Test/Model/SpecialModelNameTests.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools.Test/Model/SpecialModelNameTests.cs
index 506fb3738b2..ac02ca10f52 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools.Test/Model/SpecialModelNameTests.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools.Test/Model/SpecialModelNameTests.cs
@@ -49,7 +49,11 @@ namespace Org.OpenAPITools.Test
         [Fact]
         public void SpecialPropertyNameTest()
         {
-            // TODO unit test for the property 'SpecialPropertyName'
+            SpecialModelName s = new SpecialModelName();
+            s.SpecialPropertyName = 123l;
+            Assert.Equal("{\"$special[property.name]\":123}", JsonConvert.SerializeObject(s));
+            // comment out the following as the result is OS-dependent
+            //Assert.Equal("{\"$special[property.name]\":123}", s.ToJson());
         }
 
     }