diff --git a/requirements.txt b/requirements.txt
index 07be7e1..fc06a05 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -17,7 +17,7 @@ gunicorn==20.0.4
 importlib-metadata==1.6.0
 joblib==0.14.1
 kombu==4.6.8
-nltk==3.5
+nltk==3.6.6
 psycopg2==2.8.5
 pystache==0.5.4
 python-dateutil==2.8.1