diff --git a/docs/samples/v1alpha2/custom/kfserving-custom-model/model-server/requirements.txt b/docs/samples/v1alpha2/custom/kfserving-custom-model/model-server/requirements.txt
index e0bf22368..28b806d06 100644
--- a/docs/samples/v1alpha2/custom/kfserving-custom-model/model-server/requirements.txt
+++ b/docs/samples/v1alpha2/custom/kfserving-custom-model/model-server/requirements.txt
@@ -36,6 +36,6 @@ six==1.14.0
 table-logger==0.3.6
 torch==1.4.0
 torchvision==0.5.0
-tornado==6.0.3
+tornado==6.4.1
 urllib3==1.25.8
 websocket-client==0.57.0