diff --git a/src/proto/os_vms.pro b/src/proto/os_vms.pro
index 2ed6394..667f7ab 100644
--- a/src/proto/os_vms.pro
+++ b/src/proto/os_vms.pro
@@ -1,14 +1,14 @@
 /* os_vms.c */
-void mch_settmode __ARGS((int tmode));
-int mch_get_shellsize __ARGS((void));
-void mch_set_shellsize __ARGS((void));
-char_u *mch_getenv __ARGS((char_u *lognam));
-int mch_setenv __ARGS((char *var, char *value, int x));
-int vms_sys __ARGS((char *cmd, char *out, char *inp));
-int vms_sys_status __ARGS((int status));
-int vms_read __ARGS((char *inbuf, size_t nbytes));
-int mch_expand_wildcards __ARGS((int num_pat, char_u **pat, int *num_file, char_u ***file, int flags));
-int mch_expandpath __ARGS((garray_T *gap, char_u *path, int flags));
-void *vms_fixfilename __ARGS((void *instring));
-void vms_remove_version __ARGS((void *fname));
+extern void mch_settmode __ARGS((int tmode));
+extern int mch_get_shellsize __ARGS((void));
+extern void mch_set_shellsize __ARGS((void));
+extern char_u *mch_getenv __ARGS((char_u *lognam));
+extern int mch_setenv __ARGS((char *var, char *value, int x));
+extern int vms_sys __ARGS((char *cmd, char *out, char *inp));
+extern int vms_sys_status __ARGS((int status));
+extern int vms_read __ARGS((char *inbuf, size_t nbytes));
+extern int mch_expand_wildcards __ARGS((int num_pat, char_u **pat, int *num_file, char_u ***file, int flags));
+extern int mch_expandpath __ARGS((garray_T *gap, char_u *path, int flags));
+extern void *vms_fixfilename __ARGS((void *instring));
+extern void vms_remove_version __ARGS((void *fname));
 /* vim: set ft=c : */