Index: lib/popupBlocker.js
diff --git a/lib/popupBlocker.js b/lib/popupBlocker.js
index 464ba9e77d81ebb031d34cdafa2d4f6a0aefb11a..3c171f0aff419a2cdf35c1632e49805d6c2c902a 100644
--- a/lib/popupBlocker.js
+++ b/lib/popupBlocker.js
@@ -19,11 +19,11 @@
 
 "use strict";
 
-let {defaultMatcher} = require("matcher");
-let {BlockingFilter} = require("filterClasses");
-let {stringifyURL, isThirdParty, extractHostFromFrame} = require("url");
-let {checkWhitelisted} = require("whitelisting");
-let {logRequest} = require("devtools");
+const {defaultMatcher} = require("matcher");
+const {BlockingFilter} = require("filterClasses");
+const {stringifyURL, isThirdParty, extractHostFromFrame} = require("url");
+const {checkWhitelisted} = require("whitelisting");
+const {logRequest} = require("devtools");
 
 let loadingPopups = Object.create(null);