diff --git a/requirements.txt b/requirements.txt
index 6959508..5db7107 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -8,7 +8,7 @@ hunspell==0.4.1
 itsdangerous==0.24
 Jinja2==2.9.6
 MarkupSafe==1.0
-nltk==3.2.2
+nltk==3.4.5
 packaging==16.8
 pyparsing==2.2.0
 python-dateutil==2.6.0