diff --git a/sys/nfsclient/nfs_socket.c b/sys/nfsclient/nfs_socket.c
index cdf7cf1460d3..4391c7dbddb0 100644
--- a/sys/nfsclient/nfs_socket.c
+++ b/sys/nfsclient/nfs_socket.c
@@ -1239,11 +1239,15 @@ nfs_sigintr(struct nfsmount *nmp, struct nfsreq *rep, struct thread *td)
 		return (0);
 
 	p = td->td_proc;
+	PROC_LOCK(p);
 	tmpset = p->p_siglist;
 	SIGSETNAND(tmpset, p->p_sigmask);
 	SIGSETNAND(tmpset, p->p_sigignore);
-	if (SIGNOTEMPTY(p->p_siglist) && NFSINT_SIGMASK(tmpset))
+	if (SIGNOTEMPTY(p->p_siglist) && NFSINT_SIGMASK(tmpset)) {
+		PROC_UNLOCK(p);
 		return (EINTR);
+	}
+	PROC_UNLOCK(p);
 
 	return (0);
 }