diff --git a/packages/frontend/src/pages/settings/privacy.vue b/packages/frontend/src/pages/settings/privacy.vue
index da3d36b31a..40d9be0f60 100644
--- a/packages/frontend/src/pages/settings/privacy.vue
+++ b/packages/frontend/src/pages/settings/privacy.vue
@@ -48,7 +48,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 		<template #label>{{ i18n.ts.lockdown }}<span class="_beta">{{ i18n.ts.beta }}</span></template>
 
 		<div class="_gaps_m">
-			<MkSwitch v-model="requireSigninToViewContents" @update:modelValue="save()">
+			<MkSwitch :modelValue="requireSigninToViewContents" @update:modelValue="update_requireSigninToViewContents">
 				{{ i18n.ts._accountSettings.requireSigninToViewContents }}
 				<template #caption>
 					<div>{{ i18n.ts._accountSettings.requireSigninToViewContentsDescription1 }}</div>
@@ -172,6 +172,7 @@ import { definePageMetadata } from '@/scripts/page-metadata.js';
 import FormSlot from '@/components/form/slot.vue';
 import { formatDateTimeString } from '@/scripts/format-time-string.js';
 import MkInput from '@/components/MkInput.vue';
+import * as os from '@/os.js';
 
 const $i = signinRequired();
 
@@ -217,6 +218,19 @@ watch([makeNotesFollowersOnlyBefore, makeNotesHiddenBefore], () => {
 	save();
 });
 
+async function update_requireSigninToViewContents(value: boolean) {
+	if (value) {
+		const { canceled } = await os.confirm({
+			type: 'warning',
+			text: i18n.ts.acknowledgeNotesAndEnable,
+		});
+		if (canceled) return;
+	}
+
+	requireSigninToViewContents.value = value;
+	save();
+}
+
 function save() {
 	misskeyApi('i/update', {
 		isLocked: !!isLocked.value,