diff --git a/sciunit/__init__.py b/sciunit/__init__.py
index <HASH>..<HASH> 100644
--- a/sciunit/__init__.py
+++ b/sciunit/__init__.py
@@ -16,6 +16,7 @@ except ImportError:
     from StringIO import StringIO
 if sys.version_info.major < 3:
     FileNotFoundError = OSError
+    json.JSONDecodeError = ValueError
 
 import numpy as np
 import pandas as pd
Added JSONDecodeError definition for Python 2