diff --git a/fhem/FHEM/00_MQTT2_CLIENT.pm b/fhem/FHEM/00_MQTT2_CLIENT.pm
index 736698d61..d1a8b8e96 100644
--- a/fhem/FHEM/00_MQTT2_CLIENT.pm
+++ b/fhem/FHEM/00_MQTT2_CLIENT.pm
@@ -35,6 +35,7 @@ MQTT2_CLIENT_Initialize($)
     autocreate:no,simple,complex
     clientId
     clientOrder
+    connectTimeout
     disable:1,0
     disabledForIntervals
     disconnectAfter
@@ -294,6 +295,11 @@ MQTT2_CLIENT_Attr(@)
     $hash->{clientId} = $param[0] if($type eq "set");
   }
 
+  if($attrName eq "connectTimeout") {
+    delete($hash->{TIMEOUT});
+    $hash->{TIMEOUT} = $param[0] if($type eq "set");
+  }
+
   if($attrName eq "sslargs") {
     $hash->{sslargs} = {};
     for my $kv (split(" ",$param[0])) {
@@ -734,6 +740,12 @@ MQTT2_CLIENT_getStr($$)
       Note: Changing the attribute affects _all_ MQTT2_CLIENT instances.
       </li></br>
 
+    <a id="MQTT2_CLIENT-attr-connectTimeout"></a>
+    <li>connectTimeout &lt;seconds&gt;<br>
+      change the HTTP connect timeout, default is 4 seconds. This seems to be
+      necessary for some MQTT servers in robotic vacuum cleaners.
+      </li></br>
+
     <li><a href="#disable">disable</a><br>
         <a href="#disabledForIntervals">disabledForIntervals</a><br>
       disable dispatching of messages.