diff --git a/locales/index.d.ts b/locales/index.d.ts
index cee973a0a2..9c7cf467ba 100644
--- a/locales/index.d.ts
+++ b/locales/index.d.ts
@@ -13217,6 +13217,22 @@ export interface Locale extends ILocale {
      * Hibernated
      */
     "hibernated": string;
+    /**
+     * When replying to a post with a Content Warning, automatically use the same CW for the reply.
+     */
+    "keepCwDescription": string;
+    /**
+     * Disabled (do not keep CWs)
+     */
+    "keepCwDisabled": string;
+    /**
+     * Enabled (copy CWs verbatim)
+     */
+    "keepCwEnabled": string;
+    /**
+     * Enabled (copy CW and prepend "RE:", like email)
+     */
+    "keepCwPrependRe": string;
 }
 declare const locales: {
     [lang: string]: Locale;
diff --git a/packages/frontend/src/components/MkPostForm.vue b/packages/frontend/src/components/MkPostForm.vue
index c1d78301de..bbacdfda4d 100644
--- a/packages/frontend/src/components/MkPostForm.vue
+++ b/packages/frontend/src/components/MkPostForm.vue
@@ -373,7 +373,9 @@ if (props.specified) {
 // keep cw when reply
 if (prefer.s.keepCw && props.reply && props.reply.cw) {
 	useCw.value = true;
-	cw.value = props.reply.cw;
+	cw.value = prefer.s.keepCw === 'prepend-re'
+		? `RE: ${props.reply.cw}`
+		: props.reply.cw;
 }
 
 // apply default CW
diff --git a/packages/frontend/src/components/MkSelect.vue b/packages/frontend/src/components/MkSelect.vue
index cf4e4eda74..511a45c165 100644
--- a/packages/frontend/src/components/MkSelect.vue
+++ b/packages/frontend/src/components/MkSelect.vue
@@ -39,32 +39,34 @@ SPDX-License-Identifier: AGPL-3.0-only
 </div>
 </template>
 
-<script lang="ts" setup>
+<script lang="ts">
+type ItemOption<T extends string | number | null | boolean = string | number | null> = {
+	type?: 'option';
+	value: T;
+	label: string;
+};
+
+type ItemGroup<T extends string | number | null | boolean = string | number | null> = {
+	type: 'group';
+	label: string;
+	items: ItemOption<T>[];
+};
+
+export type MkSelectItem<T extends string | number | null | boolean = string | number | null> = ItemOption<T> | ItemGroup<T>;
+</script>
+
+<script lang="ts" setup generic="T extends string | number | null | boolean = string | number | null">
 import { onMounted, nextTick, ref, watch, computed, toRefs, useSlots } from 'vue';
 import { useInterval } from '@@/js/use-interval.js';
 import type { VNode, VNodeChild } from 'vue';
 import type { MenuItem } from '@/types/menu.js';
 import * as os from '@/os.js';
 
-type ItemOption = {
-	type?: 'option';
-	value: string | number | null;
-	label: string;
-};
-
-type ItemGroup = {
-	type: 'group';
-	label: string;
-	items: ItemOption[];
-};
-
-export type MkSelectItem = ItemOption | ItemGroup;
-
 // TODO: itemsをslot内のoptionで指定する用法は廃止する(props.itemsを必須化する)
 // see: https://github.com/misskey-dev/misskey/issues/15558
 
 const props = defineProps<{
-	modelValue: string | number | null;
+	modelValue: T;
 	required?: boolean;
 	readonly?: boolean;
 	disabled?: boolean;
@@ -73,11 +75,11 @@ const props = defineProps<{
 	inline?: boolean;
 	small?: boolean;
 	large?: boolean;
-	items?: MkSelectItem[];
+	items?: MkSelectItem<T>[];
 }>();
 
 const emit = defineEmits<{
-	(ev: 'update:modelValue', value: string | number | null): void;
+	(ev: 'update:modelValue', value: T): void;
 }>();
 
 const slots = useSlots();
diff --git a/packages/frontend/src/pages/settings/preferences.vue b/packages/frontend/src/pages/settings/preferences.vue
index 4e7568561b..ed0e3689a5 100644
--- a/packages/frontend/src/pages/settings/preferences.vue
+++ b/packages/frontend/src/pages/settings/preferences.vue
@@ -403,9 +403,13 @@ SPDX-License-Identifier: AGPL-3.0-only
 						<div class="_gaps_s">
 							<SearchMarker :keywords="['remember', 'keep', 'note', 'cw']">
 								<MkPreferenceContainer k="keepCw">
-									<MkSwitch v-model="keepCw">
+									<MkSelect v-model="keepCw">
 										<template #label><SearchLabel>{{ i18n.ts.keepCw }}</SearchLabel></template>
-									</MkSwitch>
+										<template #caption><SearchKeyword>{{ i18n.ts.keepCwDescription }}</SearchKeyword></template>
+										<option :value="false">{{ i18n.ts.keepCwDisabled }}</option>>
+										<option :value="true">{{ i18n.ts.keepCwEnabled }}</option>>
+										<option value="prepend-re">{{ i18n.ts.keepCwPrependRe }}</option>
+									</MkSelect>
 								</MkPreferenceContainer>
 							</SearchMarker>
 
diff --git a/packages/frontend/src/preferences/def.ts b/packages/frontend/src/preferences/def.ts
index 22059041d1..fb795b1b7a 100644
--- a/packages/frontend/src/preferences/def.ts
+++ b/packages/frontend/src/preferences/def.ts
@@ -120,7 +120,7 @@ export const PREF_DEF = {
 		default: false,
 	},
 	keepCw: {
-		default: true,
+		default: true as boolean | 'prepend-re',
 	},
 	rememberNoteVisibility: {
 		default: false,
diff --git a/sharkey-locales/en-US.yml b/sharkey-locales/en-US.yml
index 4196e3ea09..d495af766e 100644
--- a/sharkey-locales/en-US.yml
+++ b/sharkey-locales/en-US.yml
@@ -614,3 +614,8 @@ bubble: "Bubble"
 verified: "Verified"
 notVerified: "Not Verified"
 hibernated: "Hibernated"
+
+keepCwDescription: "When replying to a post with a Content Warning, automatically use the same CW for the reply."
+keepCwDisabled: "Disabled (do not keep CWs)"
+keepCwEnabled: "Enabled (copy CWs verbatim)"
+keepCwPrependRe: "Enabled (copy CW and prepend \"RE:\", like email)"