diff --git a/backend/python/middleLayer/contractApi/requirements.txt b/backend/python/middleLayer/contractApi/requirements.txt
index fcd8c01..e9b4886 100644
--- a/backend/python/middleLayer/contractApi/requirements.txt
+++ b/backend/python/middleLayer/contractApi/requirements.txt
@@ -5,5 +5,5 @@ Flask==0.12.2
 requests==2.18.4
 flask_restplus==0.12.1
 Werkzeug==0.14.1
-Flask_Cors==3.0.7
+Flask_Cors==3.0.9
 base58==1.0.3