diff --git a/src/inverted_index/requirements.txt b/src/inverted_index/requirements.txt
index 450ebbc..9bb9cff 100644
--- a/src/inverted_index/requirements.txt
+++ b/src/inverted_index/requirements.txt
@@ -1 +1 @@
-nltk==3.4
\ No newline at end of file
+nltk==3.6.6
\ No newline at end of file