diff --git a/requirements.txt b/requirements.txt
index d54c061..d43225a 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,5 @@
 h5py==2.7.1
-nltk==3.6.6
+nltk==3.9
 pandas==0.19.1
 scipy==1.10.0
 Keras==2.1.4