diff --git a/Chapter04/Lie_to_me/requirements.txt b/Chapter04/Lie_to_me/requirements.txt
index a6ed908..c74c503 100644
--- a/Chapter04/Lie_to_me/requirements.txt
+++ b/Chapter04/Lie_to_me/requirements.txt
@@ -4,7 +4,7 @@ click==6.7
 colorama==0.3.9
 cycler==0.10.0
 decorator==4.2.1
-Flask==0.12.2
+Flask==1.0
 Flask-JSGlue==0.3.1
 Flask-SocketIO==2.9.4
 Flask-Uploads==0.2.1