diff --git a/requirements.txt b/requirements.txt
index 6b05854..0024993 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,2 +1,3 @@
 paramiko==2.4.2
-tornado==5.1.1
+tornado==5.1.1; python_version < '3.5.2'
+tornado==6.0.2; python_version >= '3.5.2'