diff --git a/scripts/ZoneMinder/lib/ZoneMinder/Database.pm b/scripts/ZoneMinder/lib/ZoneMinder/Database.pm
index dcc797bd4..173c0033c 100644
--- a/scripts/ZoneMinder/lib/ZoneMinder/Database.pm
+++ b/scripts/ZoneMinder/lib/ZoneMinder/Database.pm
@@ -208,7 +208,7 @@ sub zmDbGetMonitor {
     return undef;
   }
   my $res = $sth->execute($id);
-  if ( $res ) {
+  if ( !$res ) {
     Error("Can't execute '$sql': ".$sth->errstr());
     return undef;
   }