diff --git a/src/proto/if_cscope.pro b/src/proto/if_cscope.pro
index 0617d13..aae9edf 100644
--- a/src/proto/if_cscope.pro
+++ b/src/proto/if_cscope.pro
@@ -1,9 +1,9 @@
 /* if_cscope.c */
-void do_cscope __ARGS((exarg_T *eap));
-void do_scscope __ARGS((exarg_T *eap));
-void do_cstag __ARGS((exarg_T *eap));
-int cs_fgets __ARGS((char_u *buf, int size));
-void cs_free_tags __ARGS((void));
-void cs_print_tags __ARGS((void));
-int cs_connection __ARGS((int num, char_u *dbpath, char_u *ppath));
+extern void do_cscope __ARGS((exarg_T *eap));
+extern void do_scscope __ARGS((exarg_T *eap));
+extern void do_cstag __ARGS((exarg_T *eap));
+extern int cs_fgets __ARGS((char_u *buf, int size));
+extern void cs_free_tags __ARGS((void));
+extern void cs_print_tags __ARGS((void));
+extern int cs_connection __ARGS((int num, char_u *dbpath, char_u *ppath));
 /* vim: set ft=c : */