diff --git a/snap/hooks/post-refresh b/snap/hooks/post-refresh
index e712809c..73ca5425 100755
--- a/snap/hooks/post-refresh
+++ b/snap/hooks/post-refresh
@@ -1,6 +1,3 @@
 #!/bin/sh
-# snapd will restart snap.subiquity.subiquity-service.service for us,
-# but any processes running on the serial lines are created via
-# systemd overrides in the installer layer of the squashfs and so need
-# restarting separately.
-systemctl restart 'serial-subiquity@*.service'
+mkdir -p /run/subiquity
+touch /run/subiquity/updating
diff --git a/subiquity/server/controllers/refresh.py b/subiquity/server/controllers/refresh.py
index b5f15cce..69cb6256 100644
--- a/subiquity/server/controllers/refresh.py
+++ b/subiquity/server/controllers/refresh.py
@@ -191,7 +191,6 @@ class RefreshController(SubiquityController):
 
     @with_context()
     async def start_update(self, context):
-        open(self.app.state_path('updating'), 'w').close()
         change = await self.app.snapd.post(
             'v2/snaps/{}'.format(self.snap_name),
             {'action': 'refresh'})
diff --git a/subiquitycore/snapd.py b/subiquitycore/snapd.py
index 2977dadc..38538a5c 100644
--- a/subiquitycore/snapd.py
+++ b/subiquitycore/snapd.py
@@ -118,6 +118,9 @@ class ResponseSet:
         return _FakeFileResponse(f)
 
 
+update_marker_file = '.subiquity/run/subiquity/updating'
+
+
 class FakeSnapdConnection:
     def __init__(self, snap_data_dir, scale_factor):
         self.snap_data_dir = snap_data_dir
@@ -130,6 +133,8 @@ class FakeSnapdConnection:
 
     def post(self, path, body, **args):
         if path == "v2/snaps/subiquity" and body['action'] == 'refresh':
+            # The post-refresh hook does this in the real world.
+            open(update_marker_file, 'w').close()
             return _FakeMemoryResponse({
                 "type": "async",
                 "change": "7",