diff --git a/sys/sys/sysctl.h b/sys/sys/sysctl.h
index 3be280c5c5fd..4f25e9ac953e 100644
--- a/sys/sys/sysctl.h
+++ b/sys/sys/sysctl.h
@@ -594,6 +594,7 @@ int	sysctl_find_oid(int *name, u_int namelen, struct sysctl_oid **noid,
 __BEGIN_DECLS
 int	sysctl __P((int *, u_int, void *, size_t *, void *, size_t));
 int	sysctlbyname __P((const char *, void *, size_t *, void *, size_t));
+int	sysctlnametomib __P((const char *name, int *mibp, size_t *sizep));
 __END_DECLS
 #endif	/* _KERNEL */