diff --git a/requirements.txt b/requirements.txt
index cdd785b..e7bfb47 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -44,7 +44,7 @@ MicroHMM==0.4.3
 MicroTokenizer==0.19.0
 mock==2.0.0
 networkx==2.3
-nltk==3.4.1
+nltk==3.4.5
 numpy==1.16.2
 opencv-python==4.1.0.25
 packaging==18.0