--- a/browser/components/extensions/ext-browserAction.js
+++ b/browser/components/extensions/ext-browserAction.js
@@ -35,22 +35,24 @@ function isAncestorOrSelf(target, node) 
     }
   }
   return false;
 }
 
 // WeakMap[Extension -> BrowserAction]
 const browserActionMap = new WeakMap();
 
-const browserAreas = {
-  "navbar": CustomizableUI.AREA_NAVBAR,
-  "menupanel": CustomizableUI.AREA_PANEL,
-  "tabstrip": CustomizableUI.AREA_TABSTRIP,
-  "personaltoolbar": CustomizableUI.AREA_BOOKMARKS,
-};
+XPCOMUtils.defineLazyGetter(this, "browserAreas", () => {
+  return {
+    "navbar": CustomizableUI.AREA_NAVBAR,
+    "menupanel": CustomizableUI.AREA_PANEL,
+    "tabstrip": CustomizableUI.AREA_TABSTRIP,
+    "personaltoolbar": CustomizableUI.AREA_BOOKMARKS,
+  };
+});
 
 // Responsible for the browser_action section of the manifest as well
 // as the associated popup.
 function BrowserAction(options, extension) {
   this.extension = extension;
 
   let widgetId = makeWidgetId(extension.id);
   this.id = `${widgetId}-browser-action`;