diff --git a/requirements.txt b/requirements.txt
index d3f1cf9..128147e 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,5 @@
 Lasagne==0.2.dev1
-nltk==3.2.2
+nltk==3.6.6
 numpy==1.12.0
 pandas==0.19.2
 python-dateutil==2.6.0