diff --git a/packages/python/plotly/optional-requirements.txt b/packages/python/plotly/optional-requirements.txt
index 3a02a440624..b357da77444 100644
--- a/packages/python/plotly/optional-requirements.txt
+++ b/packages/python/plotly/optional-requirements.txt
@@ -55,3 +55,4 @@ shapely
 
 ## image uri conversion
 pillow
+tornado>=6.5 # not directly required, pinned by Snyk to avoid a vulnerability