diff --git a/fhem/FHEM/00_MQTT2_CLIENT.pm b/fhem/FHEM/00_MQTT2_CLIENT.pm
index 9c4ab4d8a..727a180ed 100644
--- a/fhem/FHEM/00_MQTT2_CLIENT.pm
+++ b/fhem/FHEM/00_MQTT2_CLIENT.pm
@@ -290,7 +290,10 @@ MQTT2_CLIENT_Read($@)
 
   if(!$reread) {
     my $buf = DevIo_SimpleRead($hash);
-    return "" if(!defined($buf));
+    if(!defined($buf)) {
+      MQTT2_CLIENT_Disco($hash);
+      return "";
+    }
     $hash->{BUF} .= $buf;
   }