diff --git a/src/proto/os_unix.pro b/src/proto/os_unix.pro
index c3a8483..6e13de6 100644
--- a/src/proto/os_unix.pro
+++ b/src/proto/os_unix.pro
@@ -37,6 +37,7 @@
 int mch_setperm(char_u *name, long perm);
 int mch_fsetperm(int fd, long perm);
 void mch_copy_sec(char_u *from_file, char_u *to_file);
+void mch_copy_xattr(char_u *from_file, char_u *to_file);
 vim_acl_T mch_get_acl(char_u *fname);
 void mch_set_acl(char_u *fname, vim_acl_T aclent);
 void mch_free_acl(vim_acl_T aclent);