diff --git a/TODO.md b/TODO.md
index c212724..de61cd8 100644
--- a/TODO.md
+++ b/TODO.md
@@ -19,6 +19,8 @@ trial run of the finished image: https://git.eeqj.de/sneak/dnswatcher/issues/149
 
 # Completed Steps
 
+- 2026-10-13: a stop before the first scan completes sends no startup
+  notification; a scan that ran to the end still sends it (closes #271).
 - 2026-10-13: a save syncs the state file to disk before renaming it into place,
   so a crash cannot leave it empty and stop the next start (closes #264).
 - 2026-10-13: a `PORT` that cannot be bound stops startup with an error naming
diff --git a/internal/watcher/cancelled_test.go b/internal/watcher/cancelled_test.go
index 5d83bc1..247ab7c 100644
--- a/internal/watcher/cancelled_test.go
+++ b/internal/watcher/cancelled_test.go
@@ -83,6 +83,30 @@ func TestCancelledCheckSavesNothing(t *testing.T) {
 	}
 }
 
+// TestStopBeforeFirstScanSendsNoStartupNotification runs a watcher with
+// the startup notification on and its context already cancelled, so the
+// first scan is cut short before its lookup is sent. The scan did not
+// complete, so no startup notification may be sent.
+func TestStopBeforeFirstScanSendsNoStartupNotification(t *testing.T) {
+	t.Parallel()
+
+	cfg := defaultTestConfig(t)
+	cfg.Hostnames = []string{testHost}
+	cfg.SendTestNotification = true
+
+	w, deps := newTestWatcher(t, cfg)
+
+	ctx, cancel := context.WithCancel(t.Context())
+	cancel()
+
+	w.Run(ctx)
+
+	notifications := deps.notifier.getNotifications()
+	if len(notifications) != 0 {
+		t.Errorf("sent %v, want no notifications", notifications)
+	}
+}
+
 // newLoggingWatcher returns a watcher for a domain and a hostname, with
 // the real resolver, that writes what it logs at warning level or above
 // into the returned buffer.
diff --git a/internal/watcher/watcher.go b/internal/watcher/watcher.go
index 8c5b17b..9b078b6 100644
--- a/internal/watcher/watcher.go
+++ b/internal/watcher/watcher.go
@@ -133,7 +133,12 @@ func (w *Watcher) Run(ctx context.Context) {
 
 	w.cleanupRemovedTargets()
 	w.RunOnce(ctx)
-	w.maybeSendTestNotification(ctx)
+
+	// RunOnce returns as usual when shutdown cuts the scan short, and
+	// the startup notification says the scan completed.
+	if ctx.Err() == nil {
+		w.maybeSendTestNotification(ctx)
+	}
 
 	dnsTicker := time.NewTicker(w.config.DNSInterval)
 	tlsTicker := time.NewTicker(w.config.TLSInterval)