diff --git a/requirements-dev.txt b/requirements-dev.txt
index 14d8740e3..79c33ee18 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -5,3 +5,4 @@ setuptools>=61.0.0
 tox
 twine
 types-lxml
+filelock>=3.20.1 # not directly required, pinned by Snyk to avoid a vulnerability