diff --git a/luigi/metrics.py b/luigi/metrics.py
index 97e70fadea..81a6d034e2 100644
--- a/luigi/metrics.py
+++ b/luigi/metrics.py
@@ -1,6 +1,7 @@
 import abc
 
 from enum import Enum
+from luigi import six
 
 
 class MetricsCollectors(Enum):
@@ -19,7 +20,8 @@ def get(cls, which):
             raise ValueError("MetricsCollectors value ' {0} ' isn't supported", which)
 
 
-class MetricsCollector(abc.ABCMeta):
+@six.add_metaclass(abc.ABCMeta)
+class MetricsCollector(object):
     """Dummy MetricsCollecter base class that can be replace by tool specific
     implementation.
     """