diff --git a/bson/objectid.py b/bson/objectid.py
index d21fd837fd..537dae9541 100644
--- a/bson/objectid.py
+++ b/bson/objectid.py
@@ -244,7 +244,10 @@ def __setstate__(self, value):
             self.__id = oid
 
     def __str__(self):
-        return binascii.hexlify(self.__id).decode()
+        return binascii.hexlify(self.__id)
+
+    def __unicode__(self):
+        return self.__str__().decode()
 
     def __repr__(self):
         return "ObjectId('%s')" % (str(self),)