diff --git a/requirements.txt b/requirements.txt
index 05f38d1..02dd97b 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -18,3 +18,4 @@ publicationstatsapi==1.2.0
 articlemetaapi==1.14.19
 altmetric==1.0.0
 tenacity==8.2.2
+zipp>=3.19.1 # not directly required, pinned by Snyk to avoid a vulnerability