diff --git a/platform/chromium/vapi-background.js b/platform/chromium/vapi-background.js
index 890af54..22e6e8d 100644
--- a/platform/chromium/vapi-background.js
+++ b/platform/chromium/vapi-background.js
@@ -251,7 +251,7 @@ vAPI.messaging.onPortMessage = function(request, port) {
     if ( request.requestId !== undefined ) {
         callback = function(response) {
             // https://github.com/gorhill/uBlock/issues/383
-            if ( port.disconnected === true ) {
+            if ( vAPI.messaging.ports.hasOwnProperty(port.name) === false ) {
                 return;
             }
             port.postMessage({
@@ -292,8 +292,6 @@ vAPI.messaging.onPortDisconnect = function(port) {
     port.onDisconnect.removeListener(vAPI.messaging.onPortDisconnect);
     port.onMessage.removeListener(vAPI.messaging.onPortMessage);
     delete vAPI.messaging.ports[port.name];
-    // https://github.com/gorhill/uBlock/issues/383
-    port.disconnected = true;
 };
 
 /******************************************************************************/