diff --git a/graphene_django/utils/testing.py b/graphene_django/utils/testing.py
index d923917..5320402 100644
--- a/graphene_django/utils/testing.py
+++ b/graphene_django/utils/testing.py
@@ -145,6 +145,6 @@ class GraphQLTestCase(GraphQLTestMixin, TestCase):
     pass
 
 
-class GraphQLTransactionTestCase(GraphQLTestMixin, TransactionTestCase)
+class GraphQLTransactionTestCase(GraphQLTestMixin, TransactionTestCase):
     pass