diff --git a/requirements_dev.txt b/requirements_dev.txt
index e17370b..398714a 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -10,3 +10,4 @@ pytest
 coverage
 pre-commit
 scikit-survival
+zipp>=3.19.1 # not directly required, pinned by Snyk to avoid a vulnerability