diff --git a/requirements-dev.txt b/requirements-dev.txt
index abadf71..2fc7468 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -2,3 +2,4 @@ invoke==0.22.1
 wheel==0.31.1
 tox==3.6.1
 twine==1.12.1
+pygments>=2.7.4 # not directly required, pinned by Snyk to avoid a vulnerability