diff --git a/build/smoke-test-requirements.txt b/build/smoke-test-requirements.txt
index 7d5ac3da00d9..2eb690c84849 100644
--- a/build/smoke-test-requirements.txt
+++ b/build/smoke-test-requirements.txt
@@ -3,4 +3,5 @@ jupyter
 numpy
 matplotlib
 pandas
-livelossplot
\ No newline at end of file
+livelossplot
+tornado>=6.4.2 # not directly required, pinned by Snyk to avoid a vulnerability
\ No newline at end of file