diff --git a/locales/en-US.yml b/locales/en-US.yml
index a8d889fc94..adc8c35476 100644
--- a/locales/en-US.yml
+++ b/locales/en-US.yml
@@ -1134,6 +1134,7 @@ deletePasskeys: "Delete passkeys"
 delete2faConfirm: "This will irreversibly delete 2FA on this account. Proceed?"
 deletePasskeysConfirm: "This will irreversibly delete all passkeys and security keys on this account. Proceed?"
 inputNotMatch: "Input does not match"
+addRe: "Add \"re:\" at the beginning of comment in reply to a post with a content warning"
 
 _sensitiveMediaDetection:
   description: "Reduces the effort of server moderation through automatically recognizing
diff --git a/locales/ja-JP.yml b/locales/ja-JP.yml
index 523df1d576..69dbd21185 100644
--- a/locales/ja-JP.yml
+++ b/locales/ja-JP.yml
@@ -987,6 +987,7 @@ showWithSparkles: "タイトルをキラキラさせる"
 youHaveUnreadAnnouncements: "未読のお知らせがあります"
 neverShow: "今後表示しない"
 remindMeLater: "また後で"
+addRe: "閲覧注意の投稿への返信で、注釈の先頭に\"re:\"を追加する"
 
 _sensitiveMediaDetection:
   description: "機械学習を使って自動でセンシティブなメディアを検出し、モデレーションに役立てられます。サーバーの負荷が少し増えます。"
diff --git a/packages/client/src/components/MkPostForm.vue b/packages/client/src/components/MkPostForm.vue
index b03d6b2c38..8c619b9bbf 100644
--- a/packages/client/src/components/MkPostForm.vue
+++ b/packages/client/src/components/MkPostForm.vue
@@ -519,10 +519,23 @@ if (props.specified) {
 	pushVisibleUser(props.specified);
 }
 
+const addRe = (s: string) => {
+	if (
+		!defaultStore.state.addRe ||
+		s.trim() === "" ||
+		s.slice(0, 3).toLowerCase() === "re:"
+	)
+		return s;
+	return `re: ${s}`;
+};
+
 // keep cw when reply
 if (defaultStore.state.keepCw && props.reply && props.reply.cw) {
 	useCw = true;
-	cw = props.reply.cw;
+	cw =
+		props.reply.user.username === $i.username
+			? props.reply.cw
+			: addRe(props.reply.cw);
 }
 
 function watchForDraft() {
diff --git a/packages/client/src/pages/settings/general.vue b/packages/client/src/pages/settings/general.vue
index e7a8183f3a..c17283c34b 100644
--- a/packages/client/src/pages/settings/general.vue
+++ b/packages/client/src/pages/settings/general.vue
@@ -71,6 +71,12 @@
 					{{ i18n.ts.reflectMayTakeTime }}</template
 				></FormSwitch
 			>
+			<FormSwitch v-model="addRe" class="_formBlock"
+				>{{ i18n.ts.addRe
+				}}<span class="_beta">{{
+					i18n.ts.originalFeature
+				}}</span></FormSwitch
+			>
 
 			<FormSelect v-model="serverDisconnectedBehavior" class="_formBlock">
 				<template #label>{{ i18n.ts.whenServerDisconnected }}</template>
@@ -357,6 +363,7 @@ const showAdminUpdates = computed(
 const showTimelineReplies = computed(
 	defaultStore.makeGetterSetter("showTimelineReplies"),
 );
+const addRe = computed(defaultStore.makeGetterSetter("addRe"));
 
 watch(swipeOnDesktop, () => {
 	defaultStore.set("swipeOnMobile", true);
diff --git a/packages/client/src/store.ts b/packages/client/src/store.ts
index 25ed553070..694d2dc953 100644
--- a/packages/client/src/store.ts
+++ b/packages/client/src/store.ts
@@ -342,6 +342,10 @@ export const defaultStore = markRaw(
 			where: "device",
 			default: false,
 		},
+		addRe: {
+			where: "account",
+			default: true,
+		},
 	}),
 );