diff --git a/requirements.txt b/requirements.txt
index c8e7ca7..8897ece 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -8,7 +8,7 @@ joblib==0.11
 msgpack-numpy==0.4.1
 msgpack-python==0.5.6
 murmurhash==0.28.0
-nltk==3.3
+nltk==3.4.5
 numpy==1.14.4
 pathlib==1.0.1
 plac==0.9.6