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..7d6bb1a 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
@@ -1,4 +1,4 @@
-Babel==1.3
+Babel==2.9.1
 Flask==0.10.1
 Flask-Babel==0.9
 Flask-Login==0.2.11