diff --git a/platform/firefox/vapi-common.js b/platform/firefox/vapi-common.js
index cbe6dc7..949b7e9 100644
--- a/platform/firefox/vapi-common.js
+++ b/platform/firefox/vapi-common.js
@@ -19,6 +19,8 @@
     Home: https://github.com/gorhill/uBlock
 */
 
+/* global sendAsyncMessage */
+
 // For background page or non-background pages
 
 /******************************************************************************/
@@ -92,6 +94,12 @@ setScriptDirection(navigator.language);
 
 /******************************************************************************/
 
+vAPI.closePopup = function() {
+    sendAsyncMessage(location.host + ':closePopup');
+};
+
+/******************************************************************************/
+
 })();
 
 /******************************************************************************/