diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5781623c93..412d6e2f51 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,7 @@
 
 ### Server
 - Feat: 全てのチャットメッセージを既読にするAPIを追加(chat/read-all)
+- Fix: アカウント削除が正常に行われないことがあった問題を修正
 
 
 ## 2025.6.0
diff --git a/packages/backend/src/core/DriveService.ts b/packages/backend/src/core/DriveService.ts
index 1945c58e5b..567bad2a2d 100644
--- a/packages/backend/src/core/DriveService.ts
+++ b/packages/backend/src/core/DriveService.ts
@@ -803,14 +803,14 @@ export class DriveService {
 			await Promise.all(promises);
 		}
 
-		this.deletePostProcess(file, isExpired, deleter);
+		await this.deletePostProcess(file, isExpired, deleter);
 	}
 
 	@bindThis
 	private async deletePostProcess(file: MiDriveFile, isExpired = false, deleter?: MiUser) {
 		// リモートファイル期限切れ削除後は直リンクにする
 		if (isExpired && file.userHost !== null && file.uri != null) {
-			this.driveFilesRepository.update(file.id, {
+			await this.driveFilesRepository.update(file.id, {
 				isLink: true,
 				url: file.uri,
 				thumbnailUrl: null,
@@ -822,7 +822,7 @@ export class DriveService {
 				webpublicAccessKey: 'webpublic-' + randomUUID(),
 			});
 		} else {
-			this.driveFilesRepository.delete(file.id);
+			await this.driveFilesRepository.delete(file.id);
 		}
 
 		this.driveChart.update(file, false);
diff --git a/packages/backend/test-federation/test/user.test.ts b/packages/backend/test-federation/test/user.test.ts
index ee69e857bc..ebbe9ff5ba 100644
--- a/packages/backend/test-federation/test/user.test.ts
+++ b/packages/backend/test-federation/test/user.test.ts
@@ -380,9 +380,7 @@ describe('User', () => {
 				strictEqual(followers.length, 1); // followed by Bob
 
 				await alice.client.request('i/delete-account', { password: alice.password });
-				// NOTE: user deletion query is slow
-				// FIXME: ensure user is removed successfully
-				await sleep(10000);
+				await sleep();
 
 				const following = await bob.client.request('users/following', { userId: bob.id });
 				strictEqual(following.length, 0); // no following relation
@@ -480,9 +478,7 @@ describe('User', () => {
 				strictEqual(followers.length, 1); // followed by Bob
 
 				await aAdmin.client.request('admin/suspend-user', { userId: alice.id });
-				// NOTE: user deletion query is slow
-				// FIXME: ensure user is removed successfully
-				await sleep(10000);
+				await sleep();
 
 				const following = await bob.client.request('users/following', { userId: bob.id });
 				strictEqual(following.length, 0); // no following relation