diff --git a/requirements.txt b/requirements.txt
index 35158f4..c219938 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
-nltk==3.5
+nltk==3.9
 pyter3==0.3
 razdel==0.5.0
 tabulate==0.8.7