diff --git a/python-server/guestbook/requirements.txt b/python-server/guestbook/requirements.txt
index 3a5e0d3..82bea1e 100644
--- a/python-server/guestbook/requirements.txt
+++ b/python-server/guestbook/requirements.txt
@@ -12,5 +12,5 @@ oauth2client>=1.3
 uritemplate>=0.6
 pyasn1==0.1.7
 pyasn1-modules==0.0.5
-rsa==3.1.4
+rsa==4.7
 simplejson>=2.5.0