diff --git a/script/local.py b/script/local.py
index db7cd2c..540a134 100644
--- a/script/local.py
+++ b/script/local.py
@@ -21,7 +21,7 @@ class RobotTCP(TcpDevice):
         try:        
             ret = robot.write(cmd)
         finally:
-            self.getLogger().info(cmd + " ret = " + ret)
+            self.getLogger().info(cmd + " ret = " + str(ret))
         return ret
 
     def mount(self, puck, sample):