diff --git a/esprima/visitor.py b/esprima/visitor.py
index ad32375..743c186 100644
--- a/esprima/visitor.py
+++ b/esprima/visitor.py
@@ -74,6 +74,9 @@ def transform(self, obj, metadata):
     def transform_Object(self, obj, metadata):
         """Called if no explicit transform function exists for an Object."""
         return obj
+    
+    def generic_transform(self, obj, metadata):
+        return obj
 
     def generic_visit(self, obj):
         return self.visit(self.visit_Object(obj))