diff --git a/fhem/FHEM/91_eventTypes.pm b/fhem/FHEM/91_eventTypes.pm
index 0e01de284..7f9c5d4fe 100644
--- a/fhem/FHEM/91_eventTypes.pm
+++ b/fhem/FHEM/91_eventTypes.pm
@@ -16,6 +16,7 @@ eventTypes_Initialize($)
   $hash->{DefFn}    = "eventTypes_Define";
   $hash->{NotifyFn} = "eventTypes_Notify";
   $hash->{ShutdownFn}="eventTypes_Shutdown";
+  $hash->{UndefFn}  = "eventTypes_Undef";
   $hash->{GetFn}    = "eventTypes_Get";
   $hash->{SetFn}    = "eventTypes_Set";
   $hash->{AttrFn}   = "eventTypes_Attr";
@@ -157,6 +158,13 @@ eventTypes_Attr(@)
 }
 
 ###################################
+sub
+eventTypes_Undef()
+{
+  delete $modules{eventTypes}{ldata};
+  return undef;
+}
+
 sub
 eventTypes_Shutdown($$)
 {
diff --git a/fhem/fhem.pl b/fhem/fhem.pl
index 357aa95c4..688f80e97 100755
--- a/fhem/fhem.pl
+++ b/fhem/fhem.pl
@@ -1618,7 +1618,7 @@ CommandSetuuid($$)
   my ($cl, $param) = @_;
   return "setuuid cannot be used after FHEM is initialized" if($init_done);
   my @a = split(" ", $param);
-  return "Please define $param first" if(!defined($defs{$a[0]}));
+  return "setuuid: Please define $a[0] first" if(!defined($defs{$a[0]}));
   return "setuuid $a[0]: duplicate value, ignoring it" if($fuuidHash{$a[1]});
   $fuuidHash{$a[1]} = $a[1];
   $defs{$a[0]}{FUUID} = $a[1];