diff --git a/graphene/test/__init__.py b/graphene/test/__init__.py
index 13b05dd3b..30e516c61 100644
--- a/graphene/test/__init__.py
+++ b/graphene/test/__init__.py
@@ -1,4 +1,4 @@
-from promise import Promise, is_thenable
+from graphql.error import format_error as format_graphql_error
 from graphql.error import GraphQLError
 
 from graphene.types.schema import Schema
@@ -31,7 +31,10 @@ def format_result(self, result):
 
     def execute(self, *args, **kwargs):
         executed = self.schema.execute(*args, **dict(self.execute_options, **kwargs))
-        if is_thenable(executed):
-            return Promise.resolve(executed).then(self.format_result)
+
+        return self.format_result(executed)
+
+    async def execute_async(self, *args, **kwargs):
+        executed = await self.schema.execute_async(*args, **dict(self.execute_options, **kwargs))
 
         return self.format_result(executed)