diff --git a/modules/betterbird/README.md b/modules/betterbird/README.md
index bc405744..e5812c95 100644
--- a/modules/betterbird/README.md
+++ b/modules/betterbird/README.md
@@ -78,7 +78,11 @@ under `/run/user/<uid>/mesh-betterbird-reminder-test/`, as the user unit
 `mesh-betterbird-reminder-test` (ended after 10 minutes at most). The profile holds the module's
 user.js and one calendar: a local `.ics` file with one event, "Mesh reminder test", whose reminder is
 due `after` seconds from the call (default 40). `carry` copies named preferences of the operator's
-profile into it (a theme, a colour switch), under the same limits as `betterbird_prefs`. Then:
+profile into it (a theme, a colour switch), under the same limits as `betterbird_prefs`. The test's own
+preferences come last in its user.js, so nothing declared or carried overrides them; one of them turns
+Betterbird's update check off (`betterbird.update.checkIntervalDays` 0), because a fresh profile checks
+at its start and, when a newer build is published, opens the About window on the operator's screen
+(seen 2026-10-12). Then:
 
 - `xorg_windows` with class `Calendar` answers the reminder window: role `AlarmWindow`, type `Dialog`,
   its depth (32: a visual with alpha, which the compositor blends), its map state;
diff --git a/modules/betterbird/cmd/betterbird-tools/betterbird_test.go b/modules/betterbird/cmd/betterbird-tools/betterbird_test.go
index 2f66d12f..2a7aec55 100644
--- a/modules/betterbird/cmd/betterbird-tools/betterbird_test.go
+++ b/modules/betterbird/cmd/betterbird-tools/betterbird_test.go
@@ -238,6 +238,13 @@ func TestTheReminderTestTouchesNothingOfTheOperatorsProfile(t *testing.T) {
 		!strings.Contains(string(user), "file:///run/user/1000/"+testUnit+"/test.ics") || strings.Contains(string(user), "someone@") {
 		t.Fatalf("%s", user)
 	}
+	// Betterbird's update check stays off, so no About window opens on the operator's screen, and the
+	// test's own preferences come last, so nothing carried or declared overrides them.
+	if !strings.Contains(string(user), `"betterbird.update.checkIntervalDays", 0`) ||
+		strings.Index(string(user), "extensions.activeThemeID") > strings.Index(string(user), "calendar.registry.meshtest.uri") ||
+		strings.Index(string(user), `"calendar.alarms.show"`) > strings.Index(string(user), "calendar.registry.meshtest.uri") {
+		t.Fatalf("%s", user)
+	}
 	// The event starts 10 minutes after the reminder, which is due 40 s from now.
 	if !strings.Contains(string(cal), "DTSTART:20270115T081040Z") || !strings.Contains(string(cal), "TRIGGER:-PT10M") ||
 		a.Due != "2027-01-15T08:00:40Z" {
diff --git a/modules/betterbird/cmd/betterbird-tools/reminder.go b/modules/betterbird/cmd/betterbird-tools/reminder.go
index 995f78c9..da31debc 100644
--- a/modules/betterbird/cmd/betterbird-tools/reminder.go
+++ b/modules/betterbird/cmd/betterbird-tools/reminder.go
@@ -55,6 +55,11 @@ func ics(now time.Time, after time.Duration, stamp string) string {
 }
 
 // testPrefs are the test profile's own preferences: its one calendar, and no first-run questions.
+//
+// betterbird.update.checkIntervalDays 0 is Betterbird's own switch for its update check (MailGlue): a
+// fresh profile has never checked, so Betterbird checks at its start and, when betterbird.eu publishes a
+// newer build than the installed one, opens the About window on the operator's screen and gives it the
+// focus (seen on the workstation 2026-10-12, novox/hq issue 345). The test is about the reminder only.
 func testPrefs(calendar string) string {
 	return strings.Join([]string{
 		`user_pref("calendar.registry.meshtest.type", "ics");`,
@@ -68,6 +73,7 @@ func testPrefs(calendar string) string {
 		`user_pref("datareporting.policy.dataSubmissionEnabled", false);`,
 		`user_pref("toolkit.telemetry.reportingpolicy.firstRun", false);`,
 		`user_pref("app.update.auto", false);`,
+		`user_pref("betterbird.update.checkIntervalDays", 0);`,
 		`user_pref("mail.rights.version", 1);`,
 		"",
 	}, "\n")
@@ -125,11 +131,13 @@ func (m *Machine) ReminderTest(after time.Duration, carry []string, stop bool) (
 	if err := os.WriteFile(calendar, []byte(ics(now, after, strconv.FormatInt(now.Unix(), 10))), 0o600); err != nil {
 		return a, err
 	}
-	user := testPrefs(strings.TrimPrefix(calendar, m.Root))
+	// The module's user.js first, then what is carried, then the test's own preferences: the last
+	// statement wins, so neither can take the test's calendar or its quiet start away.
+	user := ""
 	if mine, err := readBounded(m.home(declared)); err == nil && validUserJS(string(mine)) == nil {
-		user = string(mine) + "\n" + user
+		user = string(mine) + "\n"
 	}
-	user += strings.Join(carried, "\n") + "\n"
+	user += strings.Join(carried, "\n") + "\n" + testPrefs(strings.TrimPrefix(calendar, m.Root))
 	if err := os.WriteFile(filepath.Join(dir, "profile", "user.js"), []byte(user), 0o600); err != nil {
 		return a, err
 	}