diff --git a/requirements.txt b/requirements.txt
index 274822a61..4319fee6e 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -13,7 +13,7 @@ joblib==0.13.2
 kiwisolver==1.1.0
 matplotlib==3.1.0
 multiprocess==0.70.7
-nltk==3.4.1
+nltk==3.4.5
 numpy==1.16.4
 pathos==0.2.3
 Pillow==6.0.0