diff --git a/include/net/pkt_sched.h b/include/net/pkt_sched.h
index 891d80d..ec030cd 100644
--- a/include/net/pkt_sched.h
+++ b/include/net/pkt_sched.h
@@ -96,7 +96,7 @@
 					struct nlattr *tab);
 void qdisc_put_rtab(struct qdisc_rate_table *tab);
 void qdisc_put_stab(struct qdisc_size_table *tab);
-void qdisc_warn_nonwc(char *txt, struct Qdisc *qdisc);
+void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc);
 int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,
 		    struct net_device *dev, struct netdev_queue *txq,
 		    spinlock_t *root_lock);
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index fd14df5..58bed75 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -563,7 +563,7 @@
 }
 EXPORT_SYMBOL(__qdisc_calculate_pkt_len);
 
-void qdisc_warn_nonwc(char *txt, struct Qdisc *qdisc)
+void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc)
 {
 	if (!(qdisc->flags & TCQ_F_WARN_NONWC)) {
 		pr_warn("%s: %s qdisc %X: is non-work-conserving?\n",
diff --git a/net/sched/sch_drr.c b/net/sched/sch_drr.c
index 8302717..7bbbfe1 100644
--- a/net/sched/sch_drr.c
+++ b/net/sched/sch_drr.c
@@ -391,8 +391,10 @@
 	while (1) {
 		cl = list_first_entry(&q->active, struct drr_class, alist);
 		skb = cl->qdisc->ops->peek(cl->qdisc);
-		if (skb == NULL)
+		if (skb == NULL) {
+			qdisc_warn_nonwc(__func__, cl->qdisc);
 			goto out;
+		}
 
 		len = qdisc_pkt_len(skb);
 		if (len <= cl->deficit) {