diff --git a/framework/test/Volo.Abp.Http.Client.Tests/Volo/Abp/Http/DynamicProxying/TestObjectToQueryString.cs b/framework/test/Volo.Abp.Http.Client.Tests/Volo/Abp/Http/DynamicProxying/TestObjectToQueryString.cs
index a27528cb77..e59d69953b 100644
--- a/framework/test/Volo.Abp.Http.Client.Tests/Volo/Abp/Http/DynamicProxying/TestObjectToQueryString.cs
+++ b/framework/test/Volo.Abp.Http.Client.Tests/Volo/Abp/Http/DynamicProxying/TestObjectToQueryString.cs
@@ -14,7 +14,7 @@ public class TestObjectToQueryString : IObjectToQueryString<List<GetParamsNameVa
     {
         if (values.IsNullOrEmpty())
         {
-            return null;
+            return Task.FromResult<string>(null);
         }
 
         var sb = new StringBuilder();