diff --git a/requirements-docs.txt b/requirements-docs.txt
index 0d2bfd4c83a39..ddf3fbd175e58 100644
--- a/requirements-docs.txt
+++ b/requirements-docs.txt
@@ -2,4 +2,5 @@ mkdocs-material~=2.7.0
 mkdocs-awesome-pages-plugin~=1.2.0
 mkdocs~=0.17.0
 pygments~=2.2.0
-pymdown-extensions~=4.10
\ No newline at end of file
+pymdown-extensions~=4.10
+tornado>=6.3.3 # not directly required, pinned by Snyk to avoid a vulnerability
\ No newline at end of file