diff --git a/requirements.txt b/requirements.txt
index a3e8fc5d3..4e3d37b66 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -10,7 +10,7 @@ dockerpty==0.4.1
 docopt==0.6.2
 enum34==1.1.6; python_version < '3.4'
 functools32==3.2.3.post2; python_version < '3.2'
-idna==2.8
+idna==2.9
 ipaddress==1.0.23
 jsonschema==3.2.0
 paramiko==2.7.1