diff --git a/requirements.txt b/requirements.txt
index 7e099ab..998aed8 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -24,7 +24,7 @@ Keras==2.1.4
 lxml==4.1.1
 Markdown==2.2.0
 mock==2.0.0
-nltk==3.2.5
+nltk==3.4.5
 numpy==1.14.1
 pbr==3.1.1
 Pillow==5.0.0