diff --git a/CHANGELOG.md b/CHANGELOG.md
index ed8a220e0d..eb5ac28487 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -21,6 +21,7 @@ You should also include the user name that made the change.
 - コンディショナルロールもバッジとして表示可能に
 - enhance(client): ロールをより簡単に付与できるように
 - enhance(client): 一度見たノートのRenoteは省略して表示するように
+- enhance(client): 迷惑になる可能性のある投稿を行う前に警告を表示
 - 一部のMFM構文をopt-outに
 
 ### Bugfixes
diff --git a/locales/ja-JP.yml b/locales/ja-JP.yml
index 031e90215f..5c919c3032 100644
--- a/locales/ja-JP.yml
+++ b/locales/ja-JP.yml
@@ -947,6 +947,10 @@ selectFromPresets: "プリセットから選択"
 achievements: "実績"
 gotInvalidResponseError: "サーバーの応答が無効です"
 gotInvalidResponseErrorDescription: "サーバーがダウンまたはメンテナンスしている可能性があります。しばらくしてから再度お試しください。"
+thisPostMayBeAnnoying: "この投稿は迷惑になる可能性があります。"
+thisPostMayBeAnnoyingHome: "ホームに投稿"
+thisPostMayBeAnnoyingCancel: "やめる"
+thisPostMayBeAnnoyingIgnore: "このまま投稿"
 
 _achievements:
   earnedAt: "獲得日時"
diff --git a/packages/frontend/src/components/MkDialog.vue b/packages/frontend/src/components/MkDialog.vue
index da4db63406..9690353432 100644
--- a/packages/frontend/src/components/MkDialog.vue
+++ b/packages/frontend/src/components/MkDialog.vue
@@ -32,7 +32,7 @@
 			<MkButton v-if="showCancelButton || input || select" inline @click="cancel">{{ cancelText ?? i18n.ts.cancel }}</MkButton>
 		</div>
 		<div v-if="actions" :class="$style.buttons">
-			<MkButton v-for="action in actions" :key="action.text" inline :primary="action.primary" @click="() => { action.callback(); close(); }">{{ action.text }}</MkButton>
+			<MkButton v-for="action in actions" :key="action.text" inline :primary="action.primary" @click="() => { action.callback(); modal?.close(); }">{{ action.text }}</MkButton>
 		</div>
 	</div>
 </MkModal>
diff --git a/packages/frontend/src/components/MkPostForm.vue b/packages/frontend/src/components/MkPostForm.vue
index a06bdecaa8..f15906c1c1 100644
--- a/packages/frontend/src/components/MkPostForm.vue
+++ b/packages/frontend/src/components/MkPostForm.vue
@@ -579,6 +579,36 @@ async function post(ev?: MouseEvent) {
 		os.popup(MkRippleEffect, { x, y }, {}, 'end');
 	}
 
+	const annoying =
+		text.includes('$[x2') ||
+		text.includes('$[x3') ||
+		text.includes('$[x4') ||
+		text.includes('$[scale') ||
+		text.includes('$[position');
+	if (annoying) {
+		const { canceled, result } = await os.actions({
+			type: 'warning',
+			text: i18n.ts.thisPostMayBeAnnoying,
+			actions: [{
+				value: 'home',
+				text: i18n.ts.thisPostMayBeAnnoyingHome,
+				primary: true,
+			}, {
+				value: 'cancel',
+				text: i18n.ts.thisPostMayBeAnnoyingCancel,
+			}, {
+				value: 'ignore',
+				text: i18n.ts.thisPostMayBeAnnoyingIgnore,
+			}],
+		});
+
+		if (canceled) return;
+		if (result === 'cancel') return;
+		if (result === 'home') {
+			visibility = 'home';
+		}
+	}
+
 	let postData = {
 		text: text === '' ? undefined : text,
 		fileIds: files.length > 0 ? files.map(f => f.id) : undefined,
diff --git a/packages/frontend/src/os.ts b/packages/frontend/src/os.ts
index 4997030669..639f4eaf17 100644
--- a/packages/frontend/src/os.ts
+++ b/packages/frontend/src/os.ts
@@ -186,6 +186,38 @@ export function confirm(props: {
 	});
 }
 
+// TODO: const T extends ... にしたい
+// https://zenn.dev/general_link/articles/813e47b7a0eef7#const-type-parameters
+export function actions<T extends {
+	value: string;
+	text: string;
+	primary?: boolean,
+}[]>(props: {
+	type: 'error' | 'info' | 'success' | 'warning' | 'waiting' | 'question';
+	title?: string | null;
+	text?: string | null;
+	actions: T;
+}): Promise<{ canceled: true; result: undefined; } | {
+	canceled: false; result: T[number]['value'];
+}> {
+	return new Promise((resolve, reject) => {
+		popup(MkDialog, {
+			...props,
+			actions: props.actions.map(a => ({
+				text: a.text,
+				primary: a.primary,
+				callback: () => {
+					resolve({ canceled: false, result: a.value });
+				},
+			})),
+		}, {
+			done: result => {
+				resolve(result ? result : { canceled: true });
+			},
+		}, 'closed');
+	});
+}
+
 export function inputText(props: {
 	type?: 'text' | 'email' | 'password' | 'url';
 	title?: string | null;