diff --git a/packages/frontend/src/os.ts b/packages/frontend/src/os.ts
index bb10cd7895..c4c545be1b 100644
--- a/packages/frontend/src/os.ts
+++ b/packages/frontend/src/os.ts
@@ -27,72 +27,67 @@ import { showMovedDialog } from '@/scripts/show-moved-dialog.js';
 
 export const openingWindowsCount = ref(0);
 
-export async function apiErrorAlert(err: Misskey.api.APIError, endpoint?: string) {
-	let title: string | undefined;
-	let text = err.message + '\n' + err.id;
-	if (err.code === 'INTERNAL_ERROR') {
-		title = i18n.ts.internalServerError;
-		text = i18n.ts.internalServerErrorDescription;
-		const date = new Date().toISOString();
-		const { result } = await actions({
-			type: 'error',
-			title,
-			text,
-			actions: [{
-				value: 'ok',
-				text: i18n.ts.gotIt,
-				primary: true,
-			}, {
-				value: 'copy',
-				text: i18n.ts.copyErrorInfo,
-			}],
-		});
-		if (result === 'copy') {
-			const errorReportText = [
-				`Info: ${JSON.stringify(err.info)}`,
-				`Date: ${date}`,
-			];
-			if (endpoint) errorReportText.unshift(`Endpoint: ${endpoint}`);
-
-			copyToClipboard(errorReportText.join('\n'));
-			success();
-		}
-		return;
-	} else if (err.code === 'RATE_LIMIT_EXCEEDED') {
-		title = i18n.ts.cannotPerformTemporary;
-		text = i18n.ts.cannotPerformTemporaryDescription;
-	} else if (err.code === 'INVALID_PARAM') {
-		title = i18n.ts.invalidParamError;
-		text = i18n.ts.invalidParamErrorDescription;
-	} else if (err.code === 'ROLE_PERMISSION_DENIED') {
-		title = i18n.ts.permissionDeniedError;
-		text = i18n.ts.permissionDeniedErrorDescription;
-	} else if (err.code.startsWith('TOO_MANY')) {
-		title = i18n.ts.youCannotCreateAnymore;
-		text = `${i18n.ts.error}: ${err.id}`;
-	} else if (err.message.startsWith('Unexpected token')) {
-		title = i18n.ts.gotInvalidResponseError;
-		text = i18n.ts.gotInvalidResponseErrorDescription;
-	}
-	alert({
-		type: 'error',
-		title,
-		text,
-	});
-}
-
 export const apiWithDialog = (<E extends keyof Misskey.Endpoints = keyof Misskey.Endpoints, P extends Misskey.Endpoints[E]['req'] = Misskey.Endpoints[E]['req']>(
 	endpoint: E,
 	data: P = {} as any,
 	token?: string | null | undefined,
+	customErrors?: Record<string, { title?: string; text: string; }>,
 ) => {
 	const promise = misskeyApi(endpoint, data, token);
-	promiseDialog(promise, null, (err) => {
-		apiErrorAlert(err);
+	promiseDialog(promise, null, async (err) => {
+		let title: string | undefined;
+		let text = err.message + '\n' + err.id;
+		if (err.code === 'INTERNAL_ERROR') {
+			title = i18n.ts.internalServerError;
+			text = i18n.ts.internalServerErrorDescription;
+			const date = new Date().toISOString();
+			const { result } = await actions({
+				type: 'error',
+				title,
+				text,
+				actions: [{
+					value: 'ok',
+					text: i18n.ts.gotIt,
+					primary: true,
+				}, {
+					value: 'copy',
+					text: i18n.ts.copyErrorInfo,
+				}],
+			});
+			if (result === 'copy') {
+				copyToClipboard(`Endpoint: ${endpoint}\nInfo: ${JSON.stringify(err.info)}\nDate: ${date}`);
+				success();
+			}
+			return;
+		} else if (err.code === 'RATE_LIMIT_EXCEEDED') {
+			title = i18n.ts.cannotPerformTemporary;
+			text = i18n.ts.cannotPerformTemporaryDescription;
+		} else if (err.code === 'INVALID_PARAM') {
+			title = i18n.ts.invalidParamError;
+			text = i18n.ts.invalidParamErrorDescription;
+		} else if (err.code === 'ROLE_PERMISSION_DENIED') {
+			title = i18n.ts.permissionDeniedError;
+			text = i18n.ts.permissionDeniedErrorDescription;
+		// eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
+		} else if (customErrors && customErrors[err.code] != null) {
+			title = customErrors[err.code].title;
+			text = customErrors[err.code].text;
+		} else if (err.code.startsWith('TOO_MANY')) {
+			title = i18n.ts.youCannotCreateAnymore;
+			text = `${i18n.ts.error}: ${err.id}`;
+		} else if (err.message.startsWith('Unexpected token')) {
+			title = i18n.ts.gotInvalidResponseError;
+			text = i18n.ts.gotInvalidResponseErrorDescription;
+		}
+		alert({
+			type: 'error',
+			title,
+			text,
+		});
 	});
 
 	return promise;
-}) as typeof misskeyApi;
+});
 
 type Unpromise<T> = T extends Promise<infer U> ? U : never;
 
diff --git a/packages/frontend/src/pages/settings/profile.vue b/packages/frontend/src/pages/settings/profile.vue
index 398cb7fd58..5ca8d0949d 100644
--- a/packages/frontend/src/pages/settings/profile.vue
+++ b/packages/frontend/src/pages/settings/profile.vue
@@ -240,26 +240,18 @@ function changeAvatar(ev) {
 			});
 		}
 
-		const updatePromise = misskeyApi('i/update', {
+		await os.apiWithDialog('i/update', {
 			avatarId: originalOrCropped.id,
-		});
-
-		os.promiseDialog(updatePromise, (updatedUser) => {
-			os.success();
-			$i.avatarId = updatedUser.avatarId;
-			$i.avatarUrl = updatedUser.avatarUrl;
+		}, undefined, {
+			'AVATAR_IS_SENSITIVE': {
+				title: i18n.ts.cannotSelectSensitiveMedia,
+				text: i18n.ts.cannotSelectSensitiveMediaDescription,
+			},
+		}).then(() => {
+			$i.avatarId = originalOrCropped.id;
+			$i.avatarUrl = originalOrCropped.url;
 			globalEvents.emit('requestClearPageCache');
 			claimAchievement('profileFilled');
-		}, (err) => {
-			if (err.code === 'AVATAR_IS_SENSITIVE') {
-				os.alert({
-					type: 'error',
-					title: i18n.ts.cannotSelectSensitiveMedia,
-					text: i18n.ts.cannotSelectSensitiveMediaDescription,
-				});
-			} else {
-				os.apiErrorAlert(err, 'i/update');
-			}
 		});
 	});
 }
@@ -300,25 +292,17 @@ function changeBanner(ev) {
 			});
 		}
 
-		const updatePromise = misskeyApi('i/update', {
+		await os.apiWithDialog('i/update', {
 			bannerId: originalOrCropped.id,
-		});
-
-		os.promiseDialog(updatePromise, (updatedUser) => {
-			os.success();
-			$i.bannerId = updatedUser.bannerId;
-			$i.bannerUrl = updatedUser.bannerUrl;
+		}, undefined, {
+			'BANNER_IS_SENSITIVE': {
+				title: i18n.ts.cannotSelectSensitiveMedia,
+				text: i18n.ts.cannotSelectSensitiveMediaDescription,
+			},
+		}).then(() => {
+			$i.bannerId = originalOrCropped.id;
+			$i.bannerUrl = originalOrCropped.url;
 			globalEvents.emit('requestClearPageCache');
-		}, (err) => {
-			if (err.code === 'BANNER_IS_SENSITIVE') {
-				os.alert({
-					type: 'error',
-					title: i18n.ts.cannotSelectSensitiveMedia,
-					text: i18n.ts.cannotSelectSensitiveMediaDescription,
-				});
-			} else {
-				os.apiErrorAlert(err, 'i/update');
-			}
 		});
 	});
 }