diff --git a/lib/workerpool.py b/lib/workerpool.py
index 0c9fa2937c76bc2403f1d8efe354fdd15ecbae1a..54b3fb7c278b75bc64f44e742173028706813f02 100644
--- a/lib/workerpool.py
+++ b/lib/workerpool.py
@@ -305,7 +305,7 @@ class WorkerPool(object):
 
     elif current_count < num_workers:
       # Create (num_workers - current_count) new workers
-      for i in xrange(num_workers - current_count):
+      for _ in xrange(num_workers - current_count):
         worker = self._worker_class(self, self._NewWorkerIdUnlocked())
         self._workers.append(worker)
         worker.start()