diff --git a/fhem/CHANGED b/fhem/CHANGED
index 93a09c5e0..53fad4efa 100644
--- a/fhem/CHANGED
+++ b/fhem/CHANGED
@@ -1,5 +1,6 @@
 # Add changes at the top of the list. Keep it in ASCII, and 80-char wide.
 # Do not insert empty lines here, update check depends on it.
+  - bugfix:  00_MQTT: small bugfix
   - feature: 98_DOIFtools: support for multiple holiday files in holiday2we for
              next timer calculation
   - change:  53_GHoma: plugs with energy measurement implemented
diff --git a/fhem/FHEM/00_MQTT.pm b/fhem/FHEM/00_MQTT.pm
index 123978b23..e698c3a99 100644
--- a/fhem/FHEM/00_MQTT.pm
+++ b/fhem/FHEM/00_MQTT.pm
@@ -815,6 +815,8 @@ sub client_start($) {
     $client->{message_ids}->{$msgid}++;
     readingsSingleUpdate($client,"transmission-state","subscribe sent",1);
   }
+  
+  return undef;
 };
 
 sub client_stop($) {