diff --git a/requirements.txt b/requirements.txt
index 1161cfe..2088e39 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -9,7 +9,7 @@ idna==2.6
 itsdangerous==0.24
 Jinja2==2.9.6
 MarkupSafe==1.0
-nltk==3.2.1
+nltk==3.4.5
 numpy==1.14.0
 pandas==0.19.1
 pysentiment==0.1.2.1