diff --git a/requirements.txt b/requirements.txt
index 68adb19..b59a01d 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,5 @@
 numpy==1.14.2
 pandas==0.22.0
 scipy==1.0.1
-nltk==3.2.5
+nltk==3.4.5
 pycorenlp==0.3.0