diff --git a/sys/kern/uipc_mbuf.c b/sys/kern/uipc_mbuf.c
index a39d2a03f117..847b4ee3e5e7 100644
--- a/sys/kern/uipc_mbuf.c
+++ b/sys/kern/uipc_mbuf.c
@@ -728,7 +728,7 @@ m_length(struct mbuf *m0, struct mbuf **last)
 	u_int len;
 
 	if ((m0->m_flags & M_PKTHDR) != 0)
-		return m0->m_pkthdr.len;
+		return (m0->m_pkthdr.len);
 
 	len = 0;
 	for (m = m0; m != NULL; m = m->m_next) {