diff --git a/src/proto/gui_xmdlg.pro b/src/proto/gui_xmdlg.pro
new file mode 100644
index 0000000..4f88c2f
--- /dev/null
+++ b/src/proto/gui_xmdlg.pro
@@ -0,0 +1,3 @@
+/* gui_xmdlg.c */
+char_u *gui_xm_select_font __ARGS((char_u *current));
+/* vim: set ft=c : */