diff --git a/Falcon.SugarApi/ApiDefinistions/ApiResponseTypeModelProvider.cs b/Falcon.SugarApi/ApiDefinistions/ApiResponseTypeModelProvider.cs
index 917cf0e..fdb8346 100644
--- a/Falcon.SugarApi/ApiDefinistions/ApiResponseTypeModelProvider.cs
+++ b/Falcon.SugarApi/ApiDefinistions/ApiResponseTypeModelProvider.cs
@@ -28,8 +28,8 @@ namespace Falcon.SugarApi.ApiDefinistions
                     }
                     var art = action.ActionMethod.ReturnType;
                     Type returnType =
-                        art.IsGenericType && art.IsAssignableFrom(typeof(Task<>)) ? art.GenericTypeArguments[0].GetGenericArguments()[0] :
-                        art;
+                        art.IsGenericType && art.GetGenericTypeDefinition() == typeof(Task<>) ?
+                        art.GenericTypeArguments[0] : art;
                     action.Filters.Add(new ProducesResponseTypeAttribute(returnType, StatusCodes.Status200OK));
                     action.Filters.Add(new ProducesResponseTypeAttribute(typeof(ExceptionModel), StatusCodes.Status400BadRequest));
                 }