diff --git a/requirements.txt b/requirements.txt
index 73fce60..1272e6c 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -6,7 +6,7 @@ httplib2==0.11.3
 hyperlink==17.3.1
 lxml==4.1.1
 networkx==2.0
-nltk==3.2.5
+nltk==3.4.5
 numpy>=1.14.1
 oauth2==1.9.0.post1
 oauthlib==2.0.7