diff --git a/memberPlumbing/ucsAccounts.py b/memberPlumbing/ucsAccounts.py
index 782bacd..979c1d0 100755
--- a/memberPlumbing/ucsAccounts.py
+++ b/memberPlumbing/ucsAccounts.py
@@ -110,7 +110,9 @@ async def _main():
                 if re.match(GROUPS_REGEX, group) is not None and value != ""
             ]
             # groups not from this script
-            other_old_groups = [g for g in user.props.groups if g[3:].startswith("MW_")]
+            other_old_groups = [
+                g for g in user.props.groups if not g[3:].startswith("MW_")
+            ]
             user.props.groups = other_old_groups + new_groups
 
             try: