diff --git a/IPython/testing/iptestcontroller.py b/IPython/testing/iptestcontroller.py
index d32e648..65377ad 100644
--- a/IPython/testing/iptestcontroller.py
+++ b/IPython/testing/iptestcontroller.py
@@ -202,7 +202,9 @@ js_test_group_names = {'js'}
 
 def run_webapp(q, nbdir, loglevel=0):
     """start the IPython Notebook, and pass port back to the queue"""
+    import os
     import IPython.html.notebookapp as nbapp
+    os.environ["IPYTHONDIR"] = nbdir
     server = nbapp.NotebookApp()
     args = ['--no-browser']
     args.append('--notebook-dir='+nbdir)