diff --git a/step5-Python-web/Tornado/async_demo/requirements.txt b/step5-Python-web/Tornado/async_demo/requirements.txt
index e270c51..27d2e28 100644
--- a/step5-Python-web/Tornado/async_demo/requirements.txt
+++ b/step5-Python-web/Tornado/async_demo/requirements.txt
@@ -1,6 +1,6 @@
 aiomysql==0.0.20
 cffi==1.14.0
-cryptography==2.8
+cryptography==3.2
 pycparser==2.19
 PyMySQL==0.9.2
 six==1.14.0