diff --git a/mistral/workbook/base.py b/mistral/workbook/base.py
index 90c19e991..19e34aa4d 100644
--- a/mistral/workbook/base.py
+++ b/mistral/workbook/base.py
@@ -131,7 +131,7 @@ class BaseSpec(object):
 
     _definitions = {}
 
-    _version = '1.0'
+    _version = '2.0'
 
     @classmethod
     def get_schema(cls, includes=['meta', 'definitions']):
@@ -349,7 +349,7 @@ class BaseListSpec(BaseSpec):
 class BaseSpecList(object):
     item_class = None
 
-    _version = '1.0'
+    _version = '2.0'
 
     def __init__(self, data):
         self.items = {}