diff --git a/.gitignore b/.gitignore
index d84a08f7b94..e337758c906 100644
--- a/.gitignore
+++ b/.gitignore
@@ -67,3 +67,6 @@ samples/client/petstore/python/.venv/
 *.pm~
 *.xml~
 *.t~
+
+samples/client/petstore/csharp/SwaggerClientTest/bin/Debug/
+samples/client/petstore/csharp/SwaggerClientTest/obj/Debug/
diff --git a/modules/swagger-codegen/src/main/resources/csharp/Configuration.mustache b/modules/swagger-codegen/src/main/resources/csharp/Configuration.mustache
index 029b38324c0..a7e5df5179c 100644
--- a/modules/swagger-codegen/src/main/resources/csharp/Configuration.mustache
+++ b/modules/swagger-codegen/src/main/resources/csharp/Configuration.mustache
@@ -38,8 +38,8 @@ namespace {{packageName}}.Client
                             )
         {
             if (apiClient == null)
-                ApiClient = ApiClient.Default;
-            else 
+                ApiClient = ApiClient.Default == null ? new ApiClient() : ApiClient.Default;
+            else
                 ApiClient = apiClient;
 
             Username = username;
diff --git a/samples/client/petstore/csharp/SwaggerClientTest/Lib/SwaggerClient/src/main/csharp/IO/Swagger/Client/Configuration.cs b/samples/client/petstore/csharp/SwaggerClientTest/Lib/SwaggerClient/src/main/csharp/IO/Swagger/Client/Configuration.cs
index 3df5d02c116..d321ad5ef82 100644
--- a/samples/client/petstore/csharp/SwaggerClientTest/Lib/SwaggerClient/src/main/csharp/IO/Swagger/Client/Configuration.cs
+++ b/samples/client/petstore/csharp/SwaggerClientTest/Lib/SwaggerClient/src/main/csharp/IO/Swagger/Client/Configuration.cs
@@ -38,8 +38,8 @@ namespace IO.Swagger.Client
                             )
         {
             if (apiClient == null)
-                ApiClient = ApiClient.Default;
-            else 
+                ApiClient = ApiClient.Default == null ? new ApiClient() : ApiClient.Default;
+            else
                 ApiClient = apiClient;
 
             Username = username;
diff --git a/samples/client/petstore/csharp/SwaggerClientTest/bin/Debug/SwaggerClientTest.dll b/samples/client/petstore/csharp/SwaggerClientTest/bin/Debug/SwaggerClientTest.dll
index f70fa971c5b..10b5d98d5fa 100755
Binary files a/samples/client/petstore/csharp/SwaggerClientTest/bin/Debug/SwaggerClientTest.dll and b/samples/client/petstore/csharp/SwaggerClientTest/bin/Debug/SwaggerClientTest.dll differ
diff --git a/samples/client/petstore/csharp/SwaggerClientTest/bin/Debug/SwaggerClientTest.dll.mdb b/samples/client/petstore/csharp/SwaggerClientTest/bin/Debug/SwaggerClientTest.dll.mdb
index d52933b2189..292442f3a88 100644
Binary files a/samples/client/petstore/csharp/SwaggerClientTest/bin/Debug/SwaggerClientTest.dll.mdb and b/samples/client/petstore/csharp/SwaggerClientTest/bin/Debug/SwaggerClientTest.dll.mdb differ
diff --git a/samples/client/petstore/csharp/SwaggerClientTest/obj/Debug/SwaggerClientTest.csproj.FilesWrittenAbsolute.txt b/samples/client/petstore/csharp/SwaggerClientTest/obj/Debug/SwaggerClientTest.csproj.FilesWrittenAbsolute.txt
index 8a50eed1027..323cad108c6 100644
--- a/samples/client/petstore/csharp/SwaggerClientTest/obj/Debug/SwaggerClientTest.csproj.FilesWrittenAbsolute.txt
+++ b/samples/client/petstore/csharp/SwaggerClientTest/obj/Debug/SwaggerClientTest.csproj.FilesWrittenAbsolute.txt
@@ -1,18 +1,9 @@
-/Users/williamcheng/Code/tmp/swagger-codegen/samples/client/petstore/csharp/SwaggerClientTest/obj/Debug/.NETFramework,Version=v4.5.AssemblyAttribute.cs
-/Users/williamcheng/Code/tmp/swagger-codegen/samples/client/petstore/csharp/SwaggerClientTest/obj/Debug/SwaggerClientTest.swagger-logo.png
-/Users/williamcheng/Code/tmp/swagger-codegen/samples/client/petstore/csharp/SwaggerClientTest/bin/Debug/SwaggerClientTest.dll.mdb
-/Users/williamcheng/Code/tmp/swagger-codegen/samples/client/petstore/csharp/SwaggerClientTest/bin/Debug/SwaggerClientTest.dll
-/Users/williamcheng/Code/tmp/swagger-codegen/samples/client/petstore/csharp/SwaggerClientTest/obj/Debug/SwaggerClientTest.dll
-/Users/williamcheng/Code/tmp/swagger-codegen/samples/client/petstore/csharp/SwaggerClientTest/obj/Debug/SwaggerClientTest.dll.mdb
-/Users/williamcheng/Code/tmp/swagger-codegen/samples/client/petstore/csharp/SwaggerClientTest/bin/Debug/Newtonsoft.Json.dll
-/Users/williamcheng/Code/tmp/swagger-codegen/samples/client/petstore/csharp/SwaggerClientTest/bin/Debug/nunit.framework.dll
-/Users/williamcheng/Code/tmp/swagger-codegen/samples/client/petstore/csharp/SwaggerClientTest/bin/Debug/RestSharp.dll
-/Users/williamcheng/Code/wing328/swagger-codegen/samples/client/petstore/csharp/SwaggerClientTest/obj/Debug/.NETFramework,Version=v4.5.AssemblyAttribute.cs
-/Users/williamcheng/Code/wing328/swagger-codegen/samples/client/petstore/csharp/SwaggerClientTest/obj/Debug/SwaggerClientTest.swagger-logo.png
-/Users/williamcheng/Code/wing328/swagger-codegen/samples/client/petstore/csharp/SwaggerClientTest/bin/Debug/SwaggerClientTest.dll.mdb
-/Users/williamcheng/Code/wing328/swagger-codegen/samples/client/petstore/csharp/SwaggerClientTest/bin/Debug/SwaggerClientTest.dll
-/Users/williamcheng/Code/wing328/swagger-codegen/samples/client/petstore/csharp/SwaggerClientTest/obj/Debug/SwaggerClientTest.dll
-/Users/williamcheng/Code/wing328/swagger-codegen/samples/client/petstore/csharp/SwaggerClientTest/obj/Debug/SwaggerClientTest.dll.mdb
-/Users/williamcheng/Code/wing328/swagger-codegen/samples/client/petstore/csharp/SwaggerClientTest/bin/Debug/Newtonsoft.Json.dll
-/Users/williamcheng/Code/wing328/swagger-codegen/samples/client/petstore/csharp/SwaggerClientTest/bin/Debug/nunit.framework.dll
-/Users/williamcheng/Code/wing328/swagger-codegen/samples/client/petstore/csharp/SwaggerClientTest/bin/Debug/RestSharp.dll
+/Users/williamcheng/Code/swagger-codegen/samples/client/petstore/csharp/SwaggerClientTest/obj/Debug/.NETFramework,Version=v4.5.AssemblyAttribute.cs
+/Users/williamcheng/Code/swagger-codegen/samples/client/petstore/csharp/SwaggerClientTest/obj/Debug/SwaggerClientTest.swagger-logo.png
+/Users/williamcheng/Code/swagger-codegen/samples/client/petstore/csharp/SwaggerClientTest/bin/Debug/SwaggerClientTest.dll.mdb
+/Users/williamcheng/Code/swagger-codegen/samples/client/petstore/csharp/SwaggerClientTest/bin/Debug/SwaggerClientTest.dll
+/Users/williamcheng/Code/swagger-codegen/samples/client/petstore/csharp/SwaggerClientTest/obj/Debug/SwaggerClientTest.dll
+/Users/williamcheng/Code/swagger-codegen/samples/client/petstore/csharp/SwaggerClientTest/obj/Debug/SwaggerClientTest.dll.mdb
+/Users/williamcheng/Code/swagger-codegen/samples/client/petstore/csharp/SwaggerClientTest/bin/Debug/Newtonsoft.Json.dll
+/Users/williamcheng/Code/swagger-codegen/samples/client/petstore/csharp/SwaggerClientTest/bin/Debug/nunit.framework.dll
+/Users/williamcheng/Code/swagger-codegen/samples/client/petstore/csharp/SwaggerClientTest/bin/Debug/RestSharp.dll
diff --git a/samples/client/petstore/csharp/SwaggerClientTest/obj/Debug/SwaggerClientTest.dll b/samples/client/petstore/csharp/SwaggerClientTest/obj/Debug/SwaggerClientTest.dll
index f70fa971c5b..10b5d98d5fa 100755
Binary files a/samples/client/petstore/csharp/SwaggerClientTest/obj/Debug/SwaggerClientTest.dll and b/samples/client/petstore/csharp/SwaggerClientTest/obj/Debug/SwaggerClientTest.dll differ