diff --git a/setup.py b/setup.py
index 049d182b..49bb88c1 100644
--- a/setup.py
+++ b/setup.py
@@ -83,6 +83,7 @@ install_requires = [
     'aiohttp~=2.0',
     'python-rapidjson-schema==0.1.1',
     'statsd==3.2.1',
+    'yarl>=0.11,<1.0',
 ]
 
 setup(