diff --git a/requirements.txt b/requirements.txt
index e1844eb..3993c11 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -4,7 +4,7 @@ editdistance==0.5.3
 flask-redis==0.4.0
 itsdangerous==2.0.1
 jinja2==3.0.3
-nltk==3.5
+nltk==3.6.6
 numpy==1.19.5
 redis==3.5.3
 scikit-learn==1.0.2