diff --git a/beat/core/worker.py b/beat/core/worker.py
index 0eb49818a5cadda5e559aaaf475b3cffd88976ea..cd9fdcb8145535b731f3880eba9f1f549cd5dc37 100755
--- a/beat/core/worker.py
+++ b/beat/core/worker.py
@@ -86,7 +86,7 @@ class WorkerController(object):
 
     def execute(self, worker, job_id, configuration):
         self.socket.send_multipart([
-          worker,
+          str(worker),
           WorkerController.EXECUTE,
           str(job_id),
           simplejson.dumps(configuration)
@@ -95,14 +95,14 @@ class WorkerController(object):
 
     def cancel(self, worker):
         self.socket.send_multipart([
-          worker,
+          str(worker),
           WorkerController.CANCEL
         ])
 
 
     def ack(self, worker):
         self.socket.send_multipart([
-          worker,
+          str(worker),
           WorkerController.ACK
         ])