diff --git a/src/proto/gui_gtk.pro b/src/proto/gui_gtk.pro
index 960d631..f1fdbe6 100644
--- a/src/proto/gui_gtk.pro
+++ b/src/proto/gui_gtk.pro
@@ -1,23 +1,23 @@
 /* gui_gtk.c */
-void gui_gtk_register_stock_icons __ARGS((void));
-void gui_mch_add_menu __ARGS((vimmenu_T *menu, int idx));
-void gui_mch_add_menu_item __ARGS((vimmenu_T *menu, int idx));
-void gui_mch_set_text_area_pos __ARGS((int x, int y, int w, int h));
-void gui_gtk_set_mnemonics __ARGS((int enable));
-void gui_mch_toggle_tearoffs __ARGS((int enable));
-void gui_mch_menu_set_tip __ARGS((vimmenu_T *menu));
-void gui_mch_destroy_menu __ARGS((vimmenu_T *menu));
-void gui_mch_set_scrollbar_thumb __ARGS((scrollbar_T *sb, long val, long size, long max));
-void gui_mch_set_scrollbar_pos __ARGS((scrollbar_T *sb, int x, int y, int w, int h));
-void gui_mch_create_scrollbar __ARGS((scrollbar_T *sb, int orient));
-void gui_mch_destroy_scrollbar __ARGS((scrollbar_T *sb));
-char_u *gui_mch_browse __ARGS((int saving, char_u *title, char_u *dflt, char_u *ext, char_u *initdir, char_u *filter));
-char_u *gui_mch_browsedir __ARGS((char_u *title, char_u *initdir));
-int gui_mch_dialog __ARGS((int type, char_u *title, char_u *message, char_u *buttons, int def_but, char_u *textfield));
-void gui_mch_show_popupmenu __ARGS((vimmenu_T *menu));
-void gui_make_popup __ARGS((char_u *path_name, int mouse_pos));
-void gui_mch_find_dialog __ARGS((exarg_T *eap));
-void gui_mch_replace_dialog __ARGS((exarg_T *eap));
-void gui_gtk_synch_fonts __ARGS((void));
-void ex_helpfind __ARGS((exarg_T *eap));
+extern void gui_gtk_register_stock_icons __ARGS((void));
+extern void gui_mch_add_menu __ARGS((vimmenu_T *menu, int idx));
+extern void gui_mch_add_menu_item __ARGS((vimmenu_T *menu, int idx));
+extern void gui_mch_set_text_area_pos __ARGS((int x, int y, int w, int h));
+extern void gui_gtk_set_mnemonics __ARGS((int enable));
+extern void gui_mch_toggle_tearoffs __ARGS((int enable));
+extern void gui_mch_menu_set_tip __ARGS((vimmenu_T *menu));
+extern void gui_mch_destroy_menu __ARGS((vimmenu_T *menu));
+extern void gui_mch_set_scrollbar_thumb __ARGS((scrollbar_T *sb, long val, long size, long max));
+extern void gui_mch_set_scrollbar_pos __ARGS((scrollbar_T *sb, int x, int y, int w, int h));
+extern void gui_mch_create_scrollbar __ARGS((scrollbar_T *sb, int orient));
+extern void gui_mch_destroy_scrollbar __ARGS((scrollbar_T *sb));
+extern char_u *gui_mch_browse __ARGS((int saving, char_u *title, char_u *dflt, char_u *ext, char_u *initdir, char_u *filter));
+extern char_u *gui_mch_browsedir __ARGS((char_u *title, char_u *initdir));
+extern int gui_mch_dialog __ARGS((int type, char_u *title, char_u *message, char_u *buttons, int def_but, char_u *textfield));
+extern void gui_mch_show_popupmenu __ARGS((vimmenu_T *menu));
+extern void gui_make_popup __ARGS((char_u *path_name, int mouse_pos));
+extern void gui_mch_find_dialog __ARGS((exarg_T *eap));
+extern void gui_mch_replace_dialog __ARGS((exarg_T *eap));
+extern void gui_gtk_synch_fonts __ARGS((void));
+extern void ex_helpfind __ARGS((exarg_T *eap));
 /* vim: set ft=c : */