diff --git a/requirements.txt b/requirements.txt
index 71c5bee..3bbfbc0 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -44,7 +44,7 @@ jsonfield==2.0.2
 kombu==4.1.0
 lru-dict==1.1.6
 mysqlclient==1.3.13
-nltk==3.2.5
+nltk==3.4.5
 numpy==1.14.2
 oauthlib==2.1.0
 parsimonious==0.8.0