diff --git a/requirements.txt b/requirements.txt
--- a/requirements.txt
+++ b/requirements.txt
@@ -25,8 +25,9 @@ wheel==0.29.0
 zope.deprecation==4.1.2
 zope.interface==4.1.3
 
-# debug
+## debug
 ipdb==0.10.1
+ipython==5.1.0
 
 # http servers
 gevent==1.1.2
@@ -38,4 +39,5 @@ waitress==1.0.1
 Pyro4==4.41
 serpent==1.15
 
+## test related requirements
 -r requirements_test.txt