diff --git a/requirements.txt b/requirements.txt
index 58bc5ad..642cc08 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -10,7 +10,7 @@ httplib2==0.9.2
 idna==2.1
 ipaddress==1.0.16
 ndg-httpsclient==0.4.2
-nltk==3.2.1
+nltk==3.4.5
 oauth2==1.9.0.post1
 oauth2client==3.0.0
 oauthlib==1.1.2