diff --git a/docs/requirements.txt b/docs/requirements.txt
index 2d459977..5c67616e 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1,3 +1,4 @@
 sphinx>=2.0.0
 sphinx_rtd_theme
 sphinxcontrib-images
+pygments>=2.7.4 # not directly required, pinned by Snyk to avoid a vulnerability