diff --git a/resdsql/NatSQL/requirements.txt b/resdsql/NatSQL/requirements.txt
index c526601..8ec5e60 100644
--- a/resdsql/NatSQL/requirements.txt
+++ b/resdsql/NatSQL/requirements.txt
@@ -1,4 +1,4 @@
-nltk==3.9.3
+nltk==3.9.4
 spacy==2.2.3
 editdistance
 https://github.com/explosion/spacy-models/releases/download/en_core_web_sm-2.2.0/en_core_web_sm-2.2.0.tar.gz