diff --git a/requirements.txt b/requirements.txt
index d3ab5e2..87daf9a 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -20,7 +20,7 @@ idna==2.8
 iso8601==0.1.12
 JSON-log-formatter==0.2.0
 mock==3.0.5
-nltk==3.2.5
+nltk==3.6.3
 psutil==5.6.2
 psycopg2==2.7.3.2
 python-dateutil==2.6.0