diff --git a/PBot/Users.pm b/PBot/Users.pm
index 12703ca7..bdf2f7a0 100644
--- a/PBot/Users.pm
+++ b/PBot/Users.pm
@@ -446,7 +446,7 @@ sub userset {
     return "To modify admin user accounts your user account must have the can-modify-admins capability.";
   }
 
-  if ($self->{pbot}->{capabilities}->exists($key) and not $self->{pbot}->{capabilities}->userhas($u, $key)) {
+  if (defined $key and $self->{pbot}->{capabilities}->exists($key) and not $self->{pbot}->{capabilities}->userhas($u, $key)) {
     return "To set the $key capability your user account must also have it." unless $self->{pbot}->{capabilities}->userhas($u, 'botowner');
   }