diff --git a/requirements.txt b/requirements.txt
index 58e128e..9f744c0 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
-nltk==3.4.5
+nltk==3.9
 numpy==1.16.3
 pandas==1.0.3
 matplotlib==3.2.1