diff --git a/docs/requirements.txt b/docs/requirements.txt
index d765b83..9bae626 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -51,7 +51,7 @@ sphinxcontrib-jsmath==1.0.1
 sphinxcontrib-qthelp==1.0.3
 sphinxcontrib-serializinghtml==1.1.4
 testpath==0.4.4
-tornado==6.3.2
+tornado==6.3.3
 traitlets==4.3.3
 urllib3==1.26.17
 webencodings==0.5.1