1 files changed, 1 insertions, 0 deletions
diff --git a/lib/priorityQueue.js b/lib/priorityQueue.js
index 147a009..d8b6016 100644
--- a/lib/priorityQueue.js
+++ b/lib/priorityQueue.js
@@ -51,6 +51,7 @@ export default function(worker, concurrency) {
             });
         }
 
+        priority = priority || 0;
         var nextNode = q._tasks.head;
         while (nextNode && priority >= nextNode.priority) {
             nextNode = nextNode.next;