diff --git a/setup.py b/setup.py
index edfd1aa..f797713 100644
--- a/setup.py
+++ b/setup.py
@@ -70,6 +70,7 @@ setuptools.setup(
         "pynacl==1.3.0",
         "trio-asyncio>=0.10.0",
         "trio>=0.13.0",
+        "async-service>=0.1.0a2,<0.2.0",
     ],
     extras_require=extras_require,
     packages=setuptools.find_packages(exclude=["tests", "tests.*"]),