diff --git a/samples/client/petstore/csharp/OpenAPIClient/src/Org.OpenAPITools/Api/FakeApi.cs b/samples/client/petstore/csharp/OpenAPIClient/src/Org.OpenAPITools/Api/FakeApi.cs
index ce37acaec65..8380cef3254 100644
--- a/samples/client/petstore/csharp/OpenAPIClient/src/Org.OpenAPITools/Api/FakeApi.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient/src/Org.OpenAPITools/Api/FakeApi.cs
@@ -2858,7 +2858,7 @@ namespace Org.OpenAPITools.Api
             }
             if (enumFormStringArray != null)
             {
-                localVarRequestOptions.FormParameters.Add("enum_form_string_array", Org.OpenAPITools.Client.ClientUtils.ParameterToString(enumFormStringArray)); // form parameter
+                localVarRequestOptions.FormParameters.Add("enum_form_string_array", Org.OpenAPITools.Client.ClientUtils.Serialize(enumFormStringArray)); // form parameter
             }
             if (enumFormString != null)
             {
@@ -2969,7 +2969,7 @@ namespace Org.OpenAPITools.Api
             }
             if (enumFormStringArray != null)
             {
-                localVarRequestOptions.FormParameters.Add("enum_form_string_array", Org.OpenAPITools.Client.ClientUtils.ParameterToString(enumFormStringArray)); // form parameter
+                localVarRequestOptions.FormParameters.Add("enum_form_string_array", Org.OpenAPITools.Client.ClientUtils.Serialize(enumFormStringArray)); // form parameter
             }
             if (enumFormString != null)
             {