diff --git a/requirements.txt b/requirements.txt
index 439cf2a..8af2127 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
-nltk==3.4.5
+nltk==3.9
 matplotlib==3.0.2
 reynir==1.5.0
 gensim==3.7.3