diff --git a/locust_chalice/requirements.txt b/locust_chalice/requirements.txt
index a04f24d..d94c71c 100644
--- a/locust_chalice/requirements.txt
+++ b/locust_chalice/requirements.txt
@@ -3,3 +3,4 @@ gevent == 1.2.2
 invokust
 git+git://github.com/HumanCellAtlas/dcp-cli#egg=hca
 git+git://github.com/HumanCellAtlas/dcp-pyjsongen@master#egg=pyjsongen
+werkzeug>=3.0.1 # not directly required, pinned by Snyk to avoid a vulnerability