diff --git a/requirements/dev.txt b/requirements/dev.txt
index 0032fcb..c1b7d23 100644
--- a/requirements/dev.txt
+++ b/requirements/dev.txt
@@ -4,3 +4,4 @@ pytest<5.0.0
 restructuredtext-lint
 Pygments
 pytest-eventlet
+dnspython>=2.6.0rc1 # not directly required, pinned by Snyk to avoid a vulnerability