diff --git a/digdag-docs/requirements.txt b/digdag-docs/requirements.txt
index 2866521234..1cb9d8dbf0 100644
--- a/digdag-docs/requirements.txt
+++ b/digdag-docs/requirements.txt
@@ -1,3 +1,4 @@
 sphinx
 recommonmark
 sphinx_rtd_theme
+setuptools>=65.5.1 # not directly required, pinned by Snyk to avoid a vulnerability