diff --git a/master/requirements.txt b/master/requirements.txt
index 5ca388e..e1771a7 100644
--- a/master/requirements.txt
+++ b/master/requirements.txt
@@ -51,7 +51,7 @@ msgpack-python==0.4.8
 murmurhash==0.28.0
 neo4j-driver==1.5.3
 networkx==2.0
-nltk==3.2.4
+nltk==3.4.5
 numpy==1.14.0
 overrides==1.9
 pandas==0.19.2