diff --git a/beat/web/common/mixins.py b/beat/web/common/mixins.py
index 0f5bd33ce4309a23783ea653f8882d604354130a..9ebcdc9d883ec90df193b3db1bd710fa15e9f955 100644
--- a/beat/web/common/mixins.py
+++ b/beat/web/common/mixins.py
@@ -58,12 +58,12 @@ class SerializerFieldsMixin(object):
         fields = None
         query_params = request.query_params
 
-        if query_params.has_key('fields'):
+        if 'fields' in query_params:
             fields = query_params['fields'].split(',')
         else:
             fields = self.get_serializer_class().Meta.default_fields
 
-        if query_params.has_key('include_fields'):
+        if 'include_fields' in query_params:
             include_fields = query_params['include_fields'].split(',')
             fields.extend(include_fields)