diff --git a/requirements.txt b/requirements.txt
index 8ffe446..a924711 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -16,7 +16,7 @@ Jinja2==2.10
 lxml==4.2.2
 MarkupSafe==1.0
 newspaper3k==0.2.6
-nltk==3.3
+nltk==3.6.3
 numpy==1.14.5
 Pillow==5.1.0
 python-dateutil==2.7.3