diff --git a/jupyterhub/app.py b/jupyterhub/app.py
index 667be204..d3d8347c 100644
--- a/jupyterhub/app.py
+++ b/jupyterhub/app.py
@@ -1439,7 +1439,7 @@ class JupyterHub(Application):
         
         for service_name, service in self._service_map.items():
             try:
-                yield service.start()
+                service.start()
             except Exception as e:
                 self.log.critical("Failed to start service %s", service_name, exc_info=True)
                 self.exit(1)
diff --git a/jupyterhub/services/service.py b/jupyterhub/services/service.py
index bf22ac94..bb3f1cf7 100644
--- a/jupyterhub/services/service.py
+++ b/jupyterhub/services/service.py
@@ -3,7 +3,7 @@
 Cases:
 
 Managed:
-  - managed by JuyterHub (always subprocess, no custom Spawners)
+  - managed by JupyterHub (always subprocess, no custom Spawners)
   - always a long-running process
   - managed services are restarted automatically if they exit unexpectedly
 Unmanaged: