diff --git a/requirements.txt b/requirements.txt
index 48e279c..a0b409f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -26,7 +26,7 @@ eth-keys==0.2.0b3
 eth-rlp==0.1.2
 eth-utils==1.0.3
 Flask==1.0.2
-Flask-Cors==3.0.6
+Flask-Cors==3.0.9
 Flask-RESTful==0.3.6
 googleapis-common-protos==1.5.3
 grpcio==1.13.0