diff --git a/setup.py b/setup.py
index 4ec5c51..e808b95 100644
--- a/setup.py
+++ b/setup.py
@@ -75,7 +75,7 @@ install_requires = [
     "dataclasses>=0.7, <1;python_version<'3.7'",
     "async_generator==1.10",
     "trio>=0.13.0",
-    "async-service>=0.1.0a4",
+    "async-service>=0.1.0a6",
     "async-exit-stack==1.0.1",
     "trio-typing>=0.3.0,<0.4.0",
 ]