diff --git a/requirements.txt b/requirements.txt
index 954f9d0..f3d1f5c 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -25,7 +25,7 @@ mistune==0.8.4
 nbconvert==5.4.1
 nbformat==4.4.0
 networkx==2.3
-nltk==3.4.1
+nltk==3.4.5
 notebook==5.7.6
 numpy==1.16.2
 pandocfilters==1.4.2