diff --git a/machine_learning_algorithms_from_scratch/code/lda/app-tic-tac-toe/requirements.txt b/machine_learning_algorithms_from_scratch/code/lda/app-tic-tac-toe/requirements.txt
index 8a61f5c..638e9c4 100644
--- a/machine_learning_algorithms_from_scratch/code/lda/app-tic-tac-toe/requirements.txt
+++ b/machine_learning_algorithms_from_scratch/code/lda/app-tic-tac-toe/requirements.txt
@@ -9,7 +9,7 @@ Flask-WTF==0.10.2
 Flask-WhooshAlchemy==0.56
 Jinja2==2.7.3
 MarkupSafe==0.23
-Werkzeug==0.9.6
+Werkzeug==0.15.5
 coverage==3.7.1
 decorator==3.4.0
 flipflop==1.0