diff --git a/requirements.txt b/requirements.txt
index 86248d40..6e174d63 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -88,7 +88,7 @@ stevedore==5.2.0; python_version >= '3.8'
 tabulate==0.9.0; python_version >= '3.7'
 toml==0.10.2; python_version >= '2.6' and python_version not in '3.0, 3.1, 3.2, 3.3'
 tomli==2.0.1; python_version >= '3.7'
-tornado==6.1; python_version >= '3.5'
+tornado==6.4; python_version >= '3.5'
 traitlets==5.14.3; python_version >= '3.7'
 trio==0.19.0; python_version >= '3.7'
 trio-websocket==0.9.2; python_version >= '3.7'