diff --git a/requirements/docs.txt b/requirements/docs.txt
index 8a00f44..0bdc4df 100644
--- a/requirements/docs.txt
+++ b/requirements/docs.txt
@@ -1,2 +1,3 @@
 sphinx-rtd-theme>=1.0
 sphinx>=4.1.2
+zipp>=3.19.1 # not directly required, pinned by Snyk to avoid a vulnerability