diff --git a/include/localization/localization.h b/include/localization/localization.h
index bf7adac..9430202 100644
--- a/include/localization/localization.h
+++ b/include/localization/localization.h
@@ -42,6 +42,8 @@ LanguageCode lang_from_sym(mrb_state *mrb, mrb_sym sym);
 
 mrb_sym lang_to_sym(mrb_state *mrb, LanguageCode code);
 
+Key key_from_sym(mrb_state *mrb, mrb_sym sym);
+
 std::string get_key_name(Key key);
 } // namespace Localization