diff --git a/src/proto/memfile.pro b/src/proto/memfile.pro
index 3983b47..6c4329a 100644
--- a/src/proto/memfile.pro
+++ b/src/proto/memfile.pro
@@ -1,18 +1,18 @@
 /* memfile.c */
-memfile_T *mf_open __ARGS((char_u *fname, int flags));
-int mf_open_file __ARGS((memfile_T *mfp, char_u *fname));
-void mf_close __ARGS((memfile_T *mfp, int del_file));
-void mf_close_file __ARGS((buf_T *buf, int getlines));
-void mf_new_page_size __ARGS((memfile_T *mfp, unsigned new_size));
-bhdr_T *mf_new __ARGS((memfile_T *mfp, int negative, int page_count));
-bhdr_T *mf_get __ARGS((memfile_T *mfp, blocknr_T nr, int page_count));
-void mf_put __ARGS((memfile_T *mfp, bhdr_T *hp, int dirty, int infile));
-void mf_free __ARGS((memfile_T *mfp, bhdr_T *hp));
-int mf_sync __ARGS((memfile_T *mfp, int flags));
-void mf_set_dirty __ARGS((memfile_T *mfp));
-int mf_release_all __ARGS((void));
-blocknr_T mf_trans_del __ARGS((memfile_T *mfp, blocknr_T old_nr));
-void mf_set_ffname __ARGS((memfile_T *mfp));
-void mf_fullname __ARGS((memfile_T *mfp));
-int mf_need_trans __ARGS((memfile_T *mfp));
+extern memfile_T *mf_open __ARGS((char_u *fname, int flags));
+extern int mf_open_file __ARGS((memfile_T *mfp, char_u *fname));
+extern void mf_close __ARGS((memfile_T *mfp, int del_file));
+extern void mf_close_file __ARGS((buf_T *buf, int getlines));
+extern void mf_new_page_size __ARGS((memfile_T *mfp, unsigned new_size));
+extern bhdr_T *mf_new __ARGS((memfile_T *mfp, int negative, int page_count));
+extern bhdr_T *mf_get __ARGS((memfile_T *mfp, blocknr_T nr, int page_count));
+extern void mf_put __ARGS((memfile_T *mfp, bhdr_T *hp, int dirty, int infile));
+extern void mf_free __ARGS((memfile_T *mfp, bhdr_T *hp));
+extern int mf_sync __ARGS((memfile_T *mfp, int flags));
+extern void mf_set_dirty __ARGS((memfile_T *mfp));
+extern int mf_release_all __ARGS((void));
+extern blocknr_T mf_trans_del __ARGS((memfile_T *mfp, blocknr_T old_nr));
+extern void mf_set_ffname __ARGS((memfile_T *mfp));
+extern void mf_fullname __ARGS((memfile_T *mfp));
+extern int mf_need_trans __ARGS((memfile_T *mfp));
 /* vim: set ft=c : */