diff --git a/sys/sys/mount.h b/sys/sys/mount.h
index 858a451f06cf..7cb8031af6ee 100644
--- a/sys/sys/mount.h
+++ b/sys/sys/mount.h
@@ -506,7 +506,7 @@ int	fstatfs(int, struct statfs *);
 int	getfh(const char *, fhandle_t *);
 int	getfsstat(struct statfs *, long, int);
 int	getmntinfo(struct statfs **, int);
-int	nmount(const char *, const char *, int, struct iovec *, int);
+int	nmount(struct iovec *, unsigned int, int);
 int	mount(const char *, const char *, int, void *);
 int	statfs(const char *, struct statfs *);
 int	unmount(const char *, int);