diff --git a/packages/frontend/src/components/MkTextarea.vue b/packages/frontend/src/components/MkTextarea.vue
index 23fdd5bfe1..696787122e 100644
--- a/packages/frontend/src/components/MkTextarea.vue
+++ b/packages/frontend/src/components/MkTextarea.vue
@@ -91,6 +91,16 @@ const onKeydown = (ev: KeyboardEvent) => {
 	if (ev.code === 'Enter') {
 		emit('enter');
 	}
+
+	if (props.code && ev.key === 'Tab') {
+		const pos = inputEl.value?.selectionStart ?? 0;
+		const posEnd = inputEl.value?.selectionEnd ?? v.value.length;
+		v.value = v.value.slice(0, pos) + '\t' + v.value.slice(posEnd);
+		nextTick(() => {
+			inputEl.value?.setSelectionRange(pos + 1, pos + 1);
+		});
+		ev.preventDefault();
+	}
 };
 
 const updated = () => {
diff --git a/packages/frontend/src/pages/flash/flash-edit.vue b/packages/frontend/src/pages/flash/flash-edit.vue
index cfda4d6556..365b054f7a 100644
--- a/packages/frontend/src/pages/flash/flash-edit.vue
+++ b/packages/frontend/src/pages/flash/flash-edit.vue
@@ -15,7 +15,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 				<template #label>{{ i18n.ts._play.summary }}</template>
 			</MkTextarea>
 			<MkButton primary @click="selectPreset">{{ i18n.ts.selectFromPresets }}<i class="ti ti-chevron-down"></i></MkButton>
-			<MkTextarea v-model="script" class="_monospace" tall spellcheck="false">
+			<MkTextarea v-model="script" code tall spellcheck="false">
 				<template #label>{{ i18n.ts._play.script }}</template>
 			</MkTextarea>
 			<div class="_buttons">
diff --git a/packages/frontend/src/pages/registry.value.vue b/packages/frontend/src/pages/registry.value.vue
index 29406ec83c..1b2cf9f237 100644
--- a/packages/frontend/src/pages/registry.value.vue
+++ b/packages/frontend/src/pages/registry.value.vue
@@ -26,7 +26,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 					</MkKeyValue>
 				</FormSplit>
 
-				<MkTextarea v-model="valueForEditor" tall class="_monospace">
+				<MkTextarea v-model="valueForEditor" tall code>
 					<template #label>{{ i18n.ts.value }} (JSON)</template>
 				</MkTextarea>
 
diff --git a/packages/frontend/src/pages/settings/custom-css.vue b/packages/frontend/src/pages/settings/custom-css.vue
index e33e778246..8e52686c12 100644
--- a/packages/frontend/src/pages/settings/custom-css.vue
+++ b/packages/frontend/src/pages/settings/custom-css.vue
@@ -7,7 +7,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 <div class="_gaps_m">
 	<FormInfo warn>{{ i18n.ts.customCssWarn }}</FormInfo>
 
-	<MkTextarea v-model="localCustomCss" manualSave tall class="_monospace" style="tab-size: 2;">
+	<MkTextarea v-model="localCustomCss" manualSave tall code style="tab-size: 2;">
 		<template #label>CSS</template>
 	</MkTextarea>
 </div>
diff --git a/packages/frontend/src/pages/settings/plugin.install.vue b/packages/frontend/src/pages/settings/plugin.install.vue
index f304d777a5..44472d47d9 100644
--- a/packages/frontend/src/pages/settings/plugin.install.vue
+++ b/packages/frontend/src/pages/settings/plugin.install.vue
@@ -7,7 +7,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 <div class="_gaps_m">
 	<FormInfo warn>{{ i18n.ts._plugin.installWarn }}</FormInfo>
 
-	<MkTextarea v-model="code" tall>
+	<MkTextarea v-model="code" tall code>
 		<template #label>{{ i18n.ts.code }}</template>
 	</MkTextarea>
 
diff --git a/packages/frontend/src/pages/settings/theme.install.vue b/packages/frontend/src/pages/settings/theme.install.vue
index c2ca53c743..0f3fbad0b7 100644
--- a/packages/frontend/src/pages/settings/theme.install.vue
+++ b/packages/frontend/src/pages/settings/theme.install.vue
@@ -5,7 +5,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 
 <template>
 <div class="_gaps_m">
-	<MkTextarea v-model="installThemeCode">
+	<MkTextarea v-model="installThemeCode" code>
 		<template #label>{{ i18n.ts._theme.code }}</template>
 	</MkTextarea>
 
diff --git a/packages/frontend/src/pages/theme-editor.vue b/packages/frontend/src/pages/theme-editor.vue
index 0d137137fc..c4138e23de 100644
--- a/packages/frontend/src/pages/theme-editor.vue
+++ b/packages/frontend/src/pages/theme-editor.vue
@@ -51,7 +51,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 				<template #label>{{ i18n.ts.editCode }}</template>
 
 				<div class="_gaps_m">
-					<MkTextarea v-model="themeCode" tall>
+					<MkTextarea v-model="themeCode" tall code>
 						<template #label>{{ i18n.ts._theme.code }}</template>
 					</MkTextarea>
 					<MkButton primary @click="applyThemeCode">{{ i18n.ts.apply }}</MkButton>