diff --git a/web/includes/Monitor.php b/web/includes/Monitor.php
index 1e85d90ce..4dd2e6a2a 100644
--- a/web/includes/Monitor.php
+++ b/web/includes/Monitor.php
@@ -171,7 +171,7 @@ private $control_fields = array(
     }
   }
   public function getStreamSrc( $args, $querySep='&' ) {
-    if ( isset($this->{'ServerId'}) ) {
+    if ( isset($this->{'ServerId'}) and $this->{'ServerId'} ) {
       $Server = new Server( $this->{'ServerId'} );
       $streamSrc = ZM_BASE_PROTOCOL.'://'.$Server->Hostname().ZM_PATH_ZMS;
     } else {