diff --git a/requirements.txt b/requirements.txt
index 5be3d0e..515a684 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,3 +1,4 @@
 nose
 sphinx
-schema
\ No newline at end of file
+schema
+pygments>=2.7.4 # not directly required, pinned by Snyk to avoid a vulnerability
\ No newline at end of file