diff --git a/RAG/src/chain_server/requirements.txt b/RAG/src/chain_server/requirements.txt
index 217b864ae..7c59b2b9b 100644
--- a/RAG/src/chain_server/requirements.txt
+++ b/RAG/src/chain_server/requirements.txt
@@ -28,4 +28,4 @@ httpx==0.26.0
 bleach==6.1.0
 flatdict==4.0.1
 chardet==5.2.0
-nltk==3.8.1
+nltk==3.9.4