diff --git a/requirements.txt b/requirements.txt
index 237f18f..317cb5f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -30,7 +30,7 @@ matplotlib==2.0.2
 mock==2.0.0
 murmurhash==0.26.4
 networkx==1.11
-nltk==3.2.4
+nltk==3.4.5
 numpy==1.13.1
 olefile==0.44
 opencv-python==3.3.0.10