diff --git a/flask-app/requirements.txt b/flask-app/requirements.txt
index 0997eec..fae29ef 100644
--- a/flask-app/requirements.txt
+++ b/flask-app/requirements.txt
@@ -3,7 +3,7 @@ Flask==0.12.2
 itsdangerous==0.24
 Jinja2==2.10
 MarkupSafe==1.0
-nltk==3.2.5
+nltk==3.4.5
 six==1.11.0
 textblob==0.14.0
 Werkzeug==0.12.2