diff --git a/lib/workqueue.c b/lib/workqueue.c
index 1d32d24..7c811ed 100644
--- a/lib/workqueue.c
+++ b/lib/workqueue.c
@@ -91,6 +91,9 @@
 void
 work_queue_free (struct work_queue *wq)
 {
+  if (wq->thread != NULL)
+    thread_cancel(wq->thread);
+  
   /* list_delete frees items via callback */
   list_delete (wq->items);
   listnode_delete (&work_queues, wq);