diff --git a/requirements.txt b/requirements.txt
index 1051bd3..73a46bb 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -21,7 +21,7 @@ lime==0.1.1.29
 Markdown==2.6.11
 matplotlib==2.1.1
 networkx==2.0
-nltk==3.2.5
+nltk==3.4.5
 numpy==1.14.0
 pandas==0.22.0
 Pillow==5.0.0