diff --git a/fhem/FHEM/33_readingsGroup.pm b/fhem/FHEM/33_readingsGroup.pm
index 5ef4f33af..d7af88c2d 100644
--- a/fhem/FHEM/33_readingsGroup.pm
+++ b/fhem/FHEM/33_readingsGroup.pm
@@ -443,7 +443,7 @@ readingsGroup_2html($)
         } else {
           my $cmd = lookup2($commands,$name,$d,$txt);
 
-          if( $cmd =~ m/^([\w-]*):(\S*)?$/ ) {
+          if( $cmd && $cmd =~ m/^([\w-]*):(\S*)?$/ ) {
             my $set = $1;
             my $values = $2;
 
@@ -566,7 +566,7 @@ readingsGroup_2html($)
         if( !$devStateIcon ) {
           $cmd = lookup2($commands,$name,$n,$v) if( !$devStateIcon );
 
-          if( $cmd =~ m/^([\w-]*):(\S*)?$/ ) {
+          if( $cmd && $cmd =~ m/^([\w-]*):(\S*)?$/ ) {
             my $set = $1;
             my $values = $2;
 
@@ -835,7 +835,7 @@ readingsGroup_Notify($$)
           }
 
           $cmd = lookup2($commands,$n,$reading,$value);
-          if( $cmd =~ m/^(\w.*):(\S.*)?$/ ) {
+          if( $cmd && $cmd =~ m/^([\w-]*):(\S*)?$/ ) {
             next;
           }