diff --git a/reana_commons/publisher.py b/reana_commons/publisher.py
index 4ef6df32..5effcba4 100644
--- a/reana_commons/publisher.py
+++ b/reana_commons/publisher.py
@@ -17,7 +17,7 @@
                      MQ_PRODUCER_MAX_RETRIES, MQ_URL, MQ_USER)
 
 
-class BasePublisher():
+class BasePublisher(object):
     """Base publisher to MQ."""
 
     def __init__(self, queue, routing_key, connection=None,