diff --git a/common/djangoapps/student/management/commands/manage_user.py b/common/djangoapps/student/management/commands/manage_user.py
index 6ac38bedee..d1fd4684fe 100644
--- a/common/djangoapps/student/management/commands/manage_user.py
+++ b/common/djangoapps/student/management/commands/manage_user.py
@@ -148,5 +148,5 @@ class Command(BaseCommand):
             )
         )
 
-        user.groups = new_groups
+        user.groups.set(new_groups)
         user.save()