diff --git a/examples/flask-kitchensink/requirements.txt b/examples/flask-kitchensink/requirements.txt
index 15ef86231..45de4835e 100644
--- a/examples/flask-kitchensink/requirements.txt
+++ b/examples/flask-kitchensink/requirements.txt
@@ -1,3 +1,3 @@
 line-bot-sdk
 flask
-werkzeug
\ No newline at end of file
+werkzeug>=0.15.4