diff --git a/sys/netpfil/ipfw/dn_aqm_pie.c b/sys/netpfil/ipfw/dn_aqm_pie.c
--- a/sys/netpfil/ipfw/dn_aqm_pie.c
+++ b/sys/netpfil/ipfw/dn_aqm_pie.c
@@ -597,8 +597,10 @@
 		}
 
 		pst = q->aqm_status;
+		dummynet_sched_lock();
 		/* increase reference count for PIE module */
 		pie_desc.ref_count++;
+		dummynet_sched_unlock();
 		
 		pst->pq = q;
 		pst->parms = pprms;
@@ -632,9 +634,9 @@
 	mtx_unlock(&pst->lock_mtx);
 	mtx_destroy(&pst->lock_mtx);
 	free(x, M_DUMMYNET);
-	DN_BH_WLOCK();
+	dummynet_sched_lock();
 	pie_desc.ref_count--;
-	DN_BH_WUNLOCK();
+	dummynet_sched_unlock();
 }
 
 /* 
diff --git a/sys/netpfil/ipfw/dn_sched_fq_pie.c b/sys/netpfil/ipfw/dn_sched_fq_pie.c
--- a/sys/netpfil/ipfw/dn_sched_fq_pie.c
+++ b/sys/netpfil/ipfw/dn_sched_fq_pie.c
@@ -581,7 +581,7 @@
 	mtx_destroy(&pst->lock_mtx);
 	psi_extra = q->psi_extra;
 
-	DN_BH_WLOCK();
+	dummynet_sched_lock();
 	psi_extra->nr_active_q--;
 
 	/* when all sub-queues are destroyed, free flows fq_pie extra vars memory */
@@ -590,7 +590,7 @@
 		free(psi_extra, M_DUMMYNET);
 		fq_pie_desc.ref_count--;
 	}
-	DN_BH_WUNLOCK();
+	dummynet_sched_unlock();
 }
 
 /* 
@@ -1061,7 +1061,9 @@
 		pie_init(&flows[i], schk);
 	}
 
+	dummynet_sched_lock();
 	fq_pie_desc.ref_count++;
+	dummynet_sched_unlock();
 
 	return 0;
 }
diff --git a/sys/netpfil/ipfw/ip_dn_private.h b/sys/netpfil/ipfw/ip_dn_private.h
--- a/sys/netpfil/ipfw/ip_dn_private.h
+++ b/sys/netpfil/ipfw/ip_dn_private.h
@@ -399,6 +399,8 @@
 #define V_dn_cfg	VNET(dn_cfg)
 
 int dummynet_io(struct mbuf **, struct ip_fw_args *);
+void dummynet_sched_lock(void);
+void dummynet_sched_unlock(void);
 void dummynet_task(void *context, int pending);
 void dn_reschedule(void);
 struct dn_pkt_tag * dn_tag_get(struct mbuf *m);
diff --git a/sys/netpfil/ipfw/ip_dummynet.c b/sys/netpfil/ipfw/ip_dummynet.c
--- a/sys/netpfil/ipfw/ip_dummynet.c
+++ b/sys/netpfil/ipfw/ip_dummynet.c
@@ -109,6 +109,18 @@
 	taskqueue_enqueue(dn_tq, &dn_task);
 }
 
+void
+dummynet_sched_lock(void)
+{
+	mtx_lock(&sched_mtx);
+}
+
+void
+dummynet_sched_unlock(void)
+{
+	mtx_unlock(&sched_mtx);
+}
+
 void
 dn_reschedule(void)
 {