diff --git a/requirements.txt b/requirements.txt
index a25826b..2edd5b0 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,3 +2,5 @@ furo
 sphinx
 sphinxcontrib-bibtex
 tabulate
+urllib3>=2.5.0 # not directly required, pinned by Snyk to avoid a vulnerability
+zipp>=3.19.1 # not directly required, pinned by Snyk to avoid a vulnerability