diff --git a/sentinel_common/requirements.txt b/sentinel_common/requirements.txt
index 393c408..5ce6d57 100644
--- a/sentinel_common/requirements.txt
+++ b/sentinel_common/requirements.txt
@@ -1,4 +1,4 @@
-nltk==3.4.1
+nltk==3.6.3
 pydantic==0.23
 pynamodb==3.3.3
 pytest==4.3.1
\ No newline at end of file