diff --git a/requirements.txt b/requirements.txt
index 335e20cd..2c002c3a 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -43,7 +43,7 @@ sphinxcontrib-jsmath==1.0.1
 sphinxcontrib-qthelp==1.0.3
 sphinxcontrib-serializinghtml==1.1.4
 sphinxcontrib-spelling==7.1.0
-tornado==6.1
+tornado==6.3.3
 urllib3==1.26.5
 watchdog==2.0.2
 zipp==3.4.1