diff --git a/CHANGELOG.md b/CHANGELOG.md
index fb2212ebd2..0d877e449c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,9 +4,10 @@
 -
 
 ### Client
+- Enhance: AiScriptAppウィジェットで構文エラーを検知してもダイアログではなくウィジェット内にエラーを表示するように
+- Enhance: /flushページでサイトキャッシュをクリアできるようになりました
 - Fix: RSSティッカーウィジェットが正しく動作しない問題を修正
 - Fix: エラー画像が横に引き伸ばされてしまう問題に対応
-- Enhance: /flushページでサイトキャッシュをクリアできるようになりました
 
 ### Server
 -
diff --git a/packages/frontend/src/widgets/WidgetAiscriptApp.vue b/packages/frontend/src/widgets/WidgetAiscriptApp.vue
index fdd4eaae06..18acd966fd 100644
--- a/packages/frontend/src/widgets/WidgetAiscriptApp.vue
+++ b/packages/frontend/src/widgets/WidgetAiscriptApp.vue
@@ -7,25 +7,26 @@ SPDX-License-Identifier: AGPL-3.0-only
 <MkContainer :showHeader="widgetProps.showHeader" class="mkw-aiscriptApp">
 	<template #header>App</template>
 	<div :class="$style.root">
-		<MkAsUi v-if="root" :component="root" :components="components" size="small"/>
+		<div v-if="isSyntaxError">Syntax error :(</div>
+		<MkAsUi v-else-if="root" :component="root" :components="components" size="small"/>
 	</div>
 </MkContainer>
 </template>
 
 <script lang="ts" setup>
 import { onMounted, ref, watch } from 'vue';
-import type { Ref } from 'vue';
 import { Interpreter, Parser } from '@syuilo/aiscript';
 import { useWidgetPropsManager } from './widget.js';
+import type { Ref } from 'vue';
 import type { WidgetComponentEmits, WidgetComponentExpose, WidgetComponentProps } from './widget.js';
 import type { FormWithDefault, GetFormResultType } from '@/utility/form.js';
+import type { AsUiComponent, AsUiRoot } from '@/aiscript/ui.js';
 import * as os from '@/os.js';
 import { aiScriptReadline, createAiScriptEnv } from '@/aiscript/api.js';
 import { $i } from '@/i.js';
 import MkAsUi from '@/components/MkAsUi.vue';
 import MkContainer from '@/components/MkContainer.vue';
 import { registerAsUiLib } from '@/aiscript/ui.js';
-import type { AsUiComponent, AsUiRoot } from '@/aiscript/ui.js';
 
 const name = 'aiscriptApp';
 
@@ -56,8 +57,11 @@ const parser = new Parser();
 
 const root = ref<AsUiRoot>();
 const components = ref<Ref<AsUiComponent>[]>([]);
+const isSyntaxError = ref(false);
 
 async function run() {
+	isSyntaxError.value = false;
+
 	const aiscript = new Interpreter({
 		...createAiScriptEnv({
 			storageKey: 'widget',
@@ -80,10 +84,7 @@ async function run() {
 	try {
 		ast = parser.parse(widgetProps.script);
 	} catch (err) {
-		os.alert({
-			type: 'error',
-			text: 'Syntax error :(',
-		});
+		isSyntaxError.value = true;
 		return;
 	}
 	try {
diff --git a/packages/frontend/src/widgets/WidgetButton.vue b/packages/frontend/src/widgets/WidgetButton.vue
index e88a960f87..f8ae03c5fd 100644
--- a/packages/frontend/src/widgets/WidgetButton.vue
+++ b/packages/frontend/src/widgets/WidgetButton.vue
@@ -52,7 +52,7 @@ const { widgetProps, configure } = useWidgetPropsManager(name,
 
 const parser = new Parser();
 
-const run = async () => {
+async function run() {
 	const aiscript = new Interpreter(createAiScriptEnv({
 		storageKey: 'widget',
 		token: $i?.token,
@@ -84,7 +84,7 @@ const run = async () => {
 			text: err instanceof Error ? err.message : String(err),
 		});
 	}
-};
+}
 
 defineExpose<WidgetComponentExpose>({
 	name,