diff --git a/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/CSharpClientCodegen.java b/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/CSharpClientCodegen.java
index 103e0100d913..0796aa9e68d6 100644
--- a/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/CSharpClientCodegen.java
+++ b/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/CSharpClientCodegen.java
@@ -210,8 +210,8 @@ public class CSharpClientCodegen extends AbstractCSharpCodegen {
setSupportsAsync(Boolean.TRUE);
setSupportsUWP(Boolean.FALSE);
setNetStandard(Boolean.TRUE);
- additionalProperties.put("supportsAsync", this.supportsUWP);
- additionalProperties.put("supportsUWP", this.supportsAsync);
+ additionalProperties.put("supportsAsync", this.supportsAsync);
+ additionalProperties.put("supportsUWP", this.supportsUWP);
additionalProperties.put("netStandard", this.netStandard);
//Tests not yet implemented for .NET Standard codegen
diff --git a/samples/client/petstore/csharp/SwaggerClient.v5/src/IO.Swagger/Api/FakeApi.cs b/samples/client/petstore/csharp/SwaggerClient.v5/src/IO.Swagger/Api/FakeApi.cs
index af9f43b9e245..379cb7d7125b 100644
--- a/samples/client/petstore/csharp/SwaggerClient.v5/src/IO.Swagger/Api/FakeApi.cs
+++ b/samples/client/petstore/csharp/SwaggerClient.v5/src/IO.Swagger/Api/FakeApi.cs
@@ -128,6 +128,111 @@ namespace IO.Swagger.Api
/// ApiResponse of Object(void)
ApiResponse