diff --git a/toolkit/components/mozintl/mozIntl.jsm b/toolkit/components/mozintl/mozIntl.jsm
index 4939a6a1e28b..f5fa318d1f72 100644
--- a/toolkit/components/mozintl/mozIntl.jsm
+++ b/toolkit/components/mozintl/mozIntl.jsm
@@ -635,6 +635,7 @@ const availableLocaleDisplayNames = {
     "tn",
     "to",
     "tr",
+    "trs",
     "ts",
     "tt",
     "tw",