diff --git a/backend/requirements.txt b/backend/requirements.txt
index cacef69..69009c4 100644
--- a/backend/requirements.txt
+++ b/backend/requirements.txt
@@ -22,7 +22,7 @@ jedi==0.11.1
 lxml==4.1.1
 Markdown==2.6.11
 mysqlclient==1.3.12
-nltk==3.2.5
+nltk==3.4.5
 numpy==1.14.2
 pandas==0.22.0
 parsel==1.4.0