diff --git a/python-agent/requirements.txt b/python-agent/requirements.txt
index de4d555..1320433 100644
--- a/python-agent/requirements.txt
+++ b/python-agent/requirements.txt
@@ -1,6 +1,6 @@
 chainer
 ws4py
-cherrypy
+cherrypy<9.0.0
 msgpack-python
 pillow
-argparse
\ No newline at end of file
+argparse