diff --git a/fhem/FHEM/33_readingsGroup.pm b/fhem/FHEM/33_readingsGroup.pm
index 0e3c4edae..7a6926d84 100644
--- a/fhem/FHEM/33_readingsGroup.pm
+++ b/fhem/FHEM/33_readingsGroup.pm
@@ -118,7 +118,7 @@ readingsGroup_updateDevices($;$)
           next if( IsIgnored($d) );
           next if( !defined($defs{$d}{$lattr}) );
           next if( $lattr ne 'IODev' && $defs{$d}{$lattr} !~ m/^$re$/);
-          next if( $lattr eq 'IODev' && $defs{$d}{$lattr}{NAME} !~ m/^$re$/);
+          next if( $lattr eq 'IODev' && $defs{$d}{$lattr}{NAME} && $defs{$d}{$lattr}{NAME} !~ m/^$re$/);
           $list{$d} = 1;
           push @devices, [$d,$device[1]];
         }