diff --git a/packages/backend/migration/1752363231063-alsoKnownAs-simple-array.js b/packages/backend/migration/1752363231063-alsoKnownAs-simple-array.js
new file mode 100644
index 0000000000..213589eeb2
--- /dev/null
+++ b/packages/backend/migration/1752363231063-alsoKnownAs-simple-array.js
@@ -0,0 +1,22 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+export class alsoKnownAsSimpleArray1752363231063 {
+	async up(queryRunner) {
+		await queryRunner.query(`ALTER TABLE "user" ADD "alsoKnownAs2" text[];`);
+		await queryRunner.query(`UPDATE "user" SET "alsoKnownAs2"=string_to_array("alsoKnownAs", ',');`);
+		await queryRunner.query(`ALTER TABLE "user" DROP COLUMN "alsoKnownAs";`);
+		await queryRunner.query(`ALTER TABLE "user" RENAME COLUMN "alsoKnownAs2" TO "alsoKnownAs";`);
+		await queryRunner.query(`COMMENT ON COLUMN "user"."alsoKnownAs" IS 'URIs the user is known as too';`);
+	}
+
+	async down(queryRunner) {
+		await queryRunner.query(`ALTER TABLE "user" ADD "alsoKnownAs2" text;`);
+		await queryRunner.query(`UPDATE "user" SET "alsoKnownAs2"=array_to_string("alsoKnownAs", ',', '');`);
+		await queryRunner.query(`ALTER TABLE "user" DROP COLUMN "alsoKnownAs";`);
+		await queryRunner.query(`ALTER TABLE "user" RENAME COLUMN "alsoKnownAs2" TO "alsoKnownAs";`);
+		await queryRunner.query(`COMMENT ON COLUMN "user"."alsoKnownAs" IS 'URIs the user is known as too';`);
+	}
+}
diff --git a/packages/backend/src/models/User.ts b/packages/backend/src/models/User.ts
index a6e9edcf5f..7d5b5a0d08 100644
--- a/packages/backend/src/models/User.ts
+++ b/packages/backend/src/models/User.ts
@@ -80,7 +80,8 @@ export class MiUser {
 	})
 	public movedAt: Date | null;
 
-	@Column('simple-array', {
+	@Column('text', {
+		array: true,
 		nullable: true,
 		comment: 'URIs the user is known as too',
 	})