diff --git a/requirements.txt b/requirements.txt
index 1316c2624..dc3159b97 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -4,3 +4,4 @@ Markdown==2.6.10
 Pelican==3.6.3
 requests==2.22.0
 urllib3==1.25.3
+idna>=3.7 # not directly required, pinned by Snyk to avoid a vulnerability