--- a/mobile/android/chrome/content/browser.js
+++ b/mobile/android/chrome/content/browser.js
@@ -3373,16 +3373,21 @@ var XPInstallObserver = {
 
   observe: function xpi_observer(aSubject, aTopic, aData) {
     switch (aTopic) {
       case "addon-install-started":
         NativeWindow.toast.show(Strings.browser.GetStringFromName("alertAddonsDownloading"), "short");
         break;
       case "addon-install-blocked":
         let installInfo = aSubject.QueryInterface(Ci.amIWebInstallInfo);
+        let win = installInfo.originatingWindow;
+        let tab = BrowserApp.getTabForWindow(win.top);
+        if (!tab)
+          return;
+
         let host = installInfo.originatingURI.host;
 
         let brandShortName = Strings.brand.GetStringFromName("brandShortName");
         let notificationName, buttons, message;
         let strings = Strings.browser;
         let enabled = true;
         try {
           enabled = Services.prefs.getBoolPref("xpinstall.enabled");
@@ -3412,17 +3417,17 @@ var XPInstallObserver = {
             label: strings.GetStringFromName("xpinstallPromptAllowButton"),
             callback: function() {
               // Kick off the install
               installInfo.install();
               return false;
             }
           }];
         }
-        NativeWindow.doorhanger.show(message, aTopic, buttons);
+        NativeWindow.doorhanger.show(message, aTopic, buttons, tab.id);
         break;
     }
   },
 
   onInstallEnded: function(aInstall, aAddon) {
     let needsRestart = false;
     if (aInstall.existingAddon && (aInstall.existingAddon.pendingOperations & AddonManager.PENDING_UPGRADE))
       needsRestart = true;