--- a/browser/base/content/browser-addons.js
+++ b/browser/base/content/browser-addons.js
@@ -85,16 +85,17 @@ const gXPInstallObserver = {
     }
 
     const anchorID = "addons-notification-icon";
 
     // Make notifications persistent
     var options = {
       displayURI: installInfo.originatingURI,
       persistent: true,
+      hideClose: true,
     };
 
     let acceptInstallation = () => {
       for (let install of installInfo.installs)
         install.install();
       installInfo = null;
 
       Services.telemetry