diff --git a/.changeset/control-not-following-kind.md b/.changeset/control-not-following-kind.md
new file mode 100644
index 0000000..8a9f5bf
--- /dev/null
+++ b/.changeset/control-not-following-kind.md
@@ -0,0 +1,8 @@
+---
+"ftw-webapp": patch
+---
+
+Notifications gain "If a device does not do what FTW asks": the box tells the
+owner when a device has not followed FTW for ten minutes, as a battery that
+charges while FTW asks it to discharge. The kind joins the push catalogue
+shared with Core and the iPhone app.
diff --git a/contract/push-catalogue.yaml b/contract/push-catalogue.yaml
index 3a56367..e428f57 100644
--- a/contract/push-catalogue.yaml
+++ b/contract/push-catalogue.yaml
@@ -44,6 +44,13 @@ events:
     # kettle must not page anyone.
     title: The house is drawing too much
     body: "{phase} is over the fuse rating."
+  - kind: control.not_following
+    # After the box's own threshold: ten minutes in which the box's answer
+    # to "Are we in control?" said a device does not do what FTW asked, as
+    # a battery that charges when told to discharge. A slow battery must not
+    # page anyone. Once until the device follows again.
+    title: A device is not following FTW
+    body: "{name} does not do what FTW asks. Open FTW to see why."
   - kind: box.unreachable
     # The one sentence the box cannot send about itself. The relay holds
     # this pre-encrypted and posts it only when the box has missed its
diff --git a/src/lib/notify/kinds.ts b/src/lib/notify/kinds.ts
index 3f18afa..599bb7b 100644
--- a/src/lib/notify/kinds.ts
+++ b/src/lib/notify/kinds.ts
@@ -16,6 +16,7 @@ export const KINDS = [
   'update.installed',
   'driver.offline',
   'fuse.over_limit',
+  'control.not_following',
   'box.unreachable',
   'cloud.granted',
   'cloud.revoked',
@@ -49,6 +50,7 @@ export const KIND_LABELS: Record<PushKind, string> = {
   'update.installed': 'When your box updates itself',
   'driver.offline': 'If a device goes quiet',
   'fuse.over_limit': 'If the house draws more than the fuse allows',
+  'control.not_following': 'If a device does not do what FTW asks',
   'box.unreachable': 'If your box goes out of reach',
   'cloud.granted': 'When FTW Cloud is turned on',
   'cloud.revoked': 'When FTW Cloud is turned off',