diff --git a/engine/core/signals.py b/engine/core/signals.py
index 6e71c485..9fce91da 100644
--- a/engine/core/signals.py
+++ b/engine/core/signals.py
@@ -77,9 +77,7 @@ def create_promocode_on_user_referring(
         attrs = instance.attributes if isinstance(instance.attributes, dict) else {}
 
         if attrs.get("referrer", ""):
-            referrer_uuid = urlsafe_base64_decode(
-                attrs.get("referrer", "")
-            ).decode()
+            referrer_uuid = urlsafe_base64_decode(attrs.get("referrer", "")).decode()
             referrer = User.objects.get(uuid=referrer_uuid)
             code = f"WELCOME-{get_random_string(6)}"
             PromoCode.objects.create(