diff --git a/src/proto/digraph.pro b/src/proto/digraph.pro
index be5be71..6821f88 100644
--- a/src/proto/digraph.pro
+++ b/src/proto/digraph.pro
@@ -1,9 +1,9 @@
 /* digraph.c */
-int do_digraph __ARGS((int c));
-int get_digraph __ARGS((int cmdline));
-int getdigraph __ARGS((int char1, int char2, int meta));
-void putdigraph __ARGS((char_u *str));
-void listdigraphs __ARGS((void));
-char_u *keymap_init __ARGS((void));
-void ex_loadkeymap __ARGS((exarg_T *eap));
+extern int do_digraph __ARGS((int c));
+extern int get_digraph __ARGS((int cmdline));
+extern int getdigraph __ARGS((int char1, int char2, int meta));
+extern void putdigraph __ARGS((char_u *str));
+extern void listdigraphs __ARGS((void));
+extern char_u *keymap_init __ARGS((void));
+extern void ex_loadkeymap __ARGS((exarg_T *eap));
 /* vim: set ft=c : */