diff --git a/requirements.txt b/requirements.txt
index 335ea74..775a811 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,7 +1,7 @@
 dill
 tqdm==4.31.1
 pandas==0.23.1
-nltk==3.4.5
+nltk==3.6.5
 boto3
 requests
 regex