diff --git a/include/unistd.h b/include/unistd.h
index 4ff516c3d7a1..0329122f7e7c 100644
--- a/include/unistd.h
+++ b/include/unistd.h
@@ -566,7 +566,7 @@ int	 setkey(const char *);
 int	 setlogin(const char *);
 int	 setloginclass(const char *);
 void	*setmode(const char *);
-int	 setpgrp(pid_t _pid, pid_t _pgrp); /* obsoleted by setpgid() */
+int	 setpgrp(pid_t, pid_t);			/* obsoleted by setpgid() */
 void	 setproctitle(const char *_fmt, ...) __printf0like(1, 2);
 int	 setresgid(gid_t, gid_t, gid_t);
 int	 setresuid(uid_t, uid_t, uid_t);