diff --git a/homeassistant/package_constraints.txt b/homeassistant/package_constraints.txt
index 481cd9da3ea..7236380d42a 100644
--- a/homeassistant/package_constraints.txt
+++ b/homeassistant/package_constraints.txt
@@ -4,6 +4,7 @@ async_timeout==3.0.1
 attrs==18.2.0
 bcrypt==3.1.4
 certifi>=2018.04.16
+idna==2.7
 jinja2>=2.10
 PyJWT==1.6.4
 cryptography==2.3.1
diff --git a/requirements_all.txt b/requirements_all.txt
index 56f1dbcb709..d252f75caaf 100644
--- a/requirements_all.txt
+++ b/requirements_all.txt
@@ -5,6 +5,7 @@ async_timeout==3.0.1
 attrs==18.2.0
 bcrypt==3.1.4
 certifi>=2018.04.16
+idna==2.7
 jinja2>=2.10
 PyJWT==1.6.4
 cryptography==2.3.1
diff --git a/setup.py b/setup.py
index 68c830190ab..f4da5411ed5 100755
--- a/setup.py
+++ b/setup.py
@@ -38,6 +38,8 @@ REQUIRES = [
     'attrs==18.2.0',
     'bcrypt==3.1.4',
     'certifi>=2018.04.16',
+    # Dec 5, 2018: Idna released 2.8, requests caps idna at <2.8, CI fails
+    'idna==2.7',
     'jinja2>=2.10',
     'PyJWT==1.6.4',
     # PyJWT has loose dependency. We want the latest one.