diff --git a/requirements.txt b/requirements.txt
index b0ba752..cc6fd3f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -53,7 +53,7 @@ nbclient==0.7.2
 nbconvert==7.2.9
 nbformat==5.7.3
 nest-asyncio==1.5.6
-nltk==3.8.1
+nltk==3.9.3
 notebook==6.5.2
 notebook_shim==0.2.2
 numpy==1.24.2
@@ -118,3 +118,4 @@ webencodings==0.5.1
 websocket-client==1.5.0
 widgetsnbextension==4.0.5
 XlsxWriter==3.0.8
+tornado>=6.5.5 # not directly required, pinned by Snyk to avoid a vulnerability