diff --git a/mozilla/modules/libpref/src/init/all.js b/mozilla/modules/libpref/src/init/all.js
index b3f7cd5340f..3f05cb2e87d 100644
--- a/mozilla/modules/libpref/src/init/all.js
+++ b/mozilla/modules/libpref/src/init/all.js
@@ -648,6 +648,7 @@ pref("network.IDN_show_punycode", false);
 
 // ccTLDs
 pref("network.IDN.whitelist.ac", true);
+pref("network.IDN.whitelist.ar", true);
 pref("network.IDN.whitelist.at", true);
 pref("network.IDN.whitelist.br", true);
 pref("network.IDN.whitelist.ch", true);