diff --git a/requirements.txt b/requirements.txt
index d27d28c..17ba1c1 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -7,3 +7,4 @@ plantumlcli>=0.0.2
 sphinx-autobuild
 -e git+https://gitee.com/huangshiyu/pytorch_sphinx_theme.git#egg=pytorch_sphinx_theme
 setuptools>=65.5.1 # not directly required, pinned by Snyk to avoid a vulnerability
+tornado>=6.3.2 # not directly required, pinned by Snyk to avoid a vulnerability