diff --git a/requirements_dev.txt b/requirements_dev.txt
index 23f65b9..c06bf75 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -8,7 +8,7 @@ coverage==4.1
 cryptography==1.4
 docutils==0.12
 flake8==2.6.0
-idna==2.1
+idna==3.10
 imagesize==0.7.1
 Jinja2==2.8
 markovify==0.4.0