diff --git a/stack/erp5/buildout.cfg b/stack/erp5/buildout.cfg
index 3cc54e37f11b044ab578a7bb14fa5258b7f887b5..f29372e11172a28c34a40400dd7a99e895af0620 100644
--- a/stack/erp5/buildout.cfg
+++ b/stack/erp5/buildout.cfg
@@ -568,6 +568,9 @@ setuptools = 2.2
 # huBarcode 1.0.0 has an issue with importing PIL.
 huBarcode = 0.63
 
+# IPython 2.0.0 requires Python Version 2.7 or above.
+ipython = 1.2.1
+
 # Known version with works
 numpy = 1.6.2
 
@@ -648,7 +651,6 @@ httplib2 = 0.8
 iniparse = 0.4
 inotifyx = 0.2.0-1
 ipdb = 0.8
-ipython = 2.0.0
 itsdangerous = 0.24
 lock-file = 2.0
 logilab-common = 0.61.0