diff --git a/requirements.txt b/requirements.txt
index e96c3a4..c77b845 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -57,7 +57,7 @@ nbconvert==5.2.1
 nbformat==4.3.0
 neo4j-driver==1.4.0
 neomodel==3.2.5
-nltk==3.2.4
+nltk==3.4.5
 notebook==5.0.0
 numexpr==2.6.2
 numpy==1.13.3