diff --git a/requirements.txt b/requirements.txt
index 9fd5005..b3b133e 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -34,7 +34,7 @@ nbclient==0.5.1
 nbconvert==6.0.7
 nbformat==5.0.8
 nest-asyncio==1.4.3
-nltk==3.5
+nltk==3.6.5
 notebook==6.4.1
 numpy==1.19.5
 openpyxl==3.0.5