diff --git a/system/user b/system/user
index 53e2a292985..26b16f0ccf7 100644
--- a/system/user
+++ b/system/user
@@ -279,7 +279,7 @@ class User(object):
             cmd.append('-g')
             cmd.append(self.group)
 
-        if self.groups is not None:
+        if self.groups is not None and len(self.groups):
             groups = self.get_groups_set()
             cmd.append('-G')
             cmd.append(','.join(groups))
@@ -1221,7 +1221,7 @@ class AIX(User):
             cmd.append('-g')
             cmd.append(self.group)
 
-        if self.groups is not None:
+        if self.groups is not None and len(self.groups):
             groups = self.get_groups_set()
             cmd.append('-G')
             cmd.append(','.join(groups))