diff --git a/xpfe/components/prefwindow/resources/locale/en-US/pref-languages.properties b/xpfe/components/prefwindow/resources/locale/en-US/pref-languages.properties
new file mode 100644
index 000000000000..bcfa2cf05dfe
--- /dev/null
+++ b/xpfe/components/prefwindow/resources/locale/en-US/pref-languages.properties
@@ -0,0 +1 @@
+illegalOtherLanguage=Not a valid language code.