diff --git a/Parser/asdl.py b/Parser/asdl.py
index 7620d58462a..4b5676cd2b7 100644
--- a/Parser/asdl.py
+++ b/Parser/asdl.py
@@ -226,7 +226,7 @@ def p_field_5(self, (type, _)):
 # not sure if any of the methods are useful yet, but I'm adding them
 # piecemeal as they seem helpful
 
-class AST:
+class AST(object):
     pass # a marker class
 
 class Module(AST):