diff --git a/modules/libpref/src/init/all.js b/modules/libpref/src/init/all.js
index 5a56fa8a5ec5..98a104b89566 100644
--- a/modules/libpref/src/init/all.js
+++ b/modules/libpref/src/init/all.js
@@ -634,6 +634,7 @@ pref("network.IDN.whitelist.fi", true);
 pref("network.IDN.whitelist.gr", true);
 pref("network.IDN.whitelist.hu", true);
 pref("network.IDN.whitelist.io", true);
+pref("network.IDN.whitelist.ir", true);
 pref("network.IDN.whitelist.is", true);
 pref("network.IDN.whitelist.jp", true);
 pref("network.IDN.whitelist.kr", true);