diff --git a/requirements.txt b/requirements.txt
index f219720..f5e4666 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -16,4 +16,4 @@ future==0.17.1
 coverage==4.5.1
 scikit-learn==0.20.0
 pillow 
-tornado==5.0.2
+tornado==6.3.3