diff --git a/requirements.txt b/requirements.txt
index 34fedf5..592c831 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,6 +1,6 @@
 streamlit==0.60.0
 numpy==1.17.2
 pythainlp==2.1.4
-nltk==3.5
+nltk==3.9
 plotly==4.1.0
 scikit_learn==0.23.1