diff --git a/sys/net/bpf.c b/sys/net/bpf.c
--- a/sys/net/bpf.c
+++ b/sys/net/bpf.c
@@ -1210,6 +1210,7 @@
 	int ready = 0;
 
 	d = (struct bpf_d *)kn->kn_hook;
+	lwkt_gettoken(&bpf_token);
 	if (d->bd_hlen != 0 ||
 	    ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) &&
 	    d->bd_slen != 0)) {