diff --git a/moto/cognitoidp/models.py b/moto/cognitoidp/models.py
index 810077faf..2f2f7e870 100644
--- a/moto/cognitoidp/models.py
+++ b/moto/cognitoidp/models.py
@@ -564,7 +564,9 @@ class CognitoIdpBackend(BaseBackend):
         user.groups.discard(group)
 
     # User
-    def admin_create_user(self, user_pool_id, username, message_action, temporary_password, attributes):
+    def admin_create_user(
+        self, user_pool_id, username, message_action, temporary_password, attributes
+    ):
         user_pool = self.user_pools.get(user_pool_id)
         if not user_pool:
             raise ResourceNotFoundError(user_pool_id)