diff --git a/oyster/scripts/signal.py b/oyster/scripts/signal.py
index ad0d32c..9284d77 100644
--- a/oyster/scripts/signal.py
+++ b/oyster/scripts/signal.py
@@ -19,7 +19,7 @@ def main():
     print '%s docs in %s' % (docs.count(), args.doc_class)
 
     for doc in docs:
-        send_task(args.task, doc['_id'])
+        send_task(args.task, (doc['_id'], ))
 
 if __name__ == '__main__':
     main()