diff --git a/test-requirements.txt b/test-requirements.txt
index 79d4b21..ca27485 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -5,3 +5,4 @@ nose
 nosexcover
 pep8
 Sphinx>=1.1
+pygments>=2.7.4 # not directly required, pinned by Snyk to avoid a vulnerability