diff --git a/CHANGELOG.md b/CHANGELOG.md
index f6d782c51..2ce3065a1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,13 @@
 
 -->
 
+## 12.x.x (unreleased)
+
+### Improvements
+
+### Bugfixes
+- チャンネルを作成しているとアカウントを削除できないのを修正
+
 ## 12.88.0 (2021/08/17)
 
 ### Features
diff --git a/migration/1629288472000-fix-channel-userId.ts b/migration/1629288472000-fix-channel-userId.ts
new file mode 100644
index 000000000..cd8f81bb0
--- /dev/null
+++ b/migration/1629288472000-fix-channel-userId.ts
@@ -0,0 +1,14 @@
+import {MigrationInterface, QueryRunner} from "typeorm";
+
+export class fixChannelUserId1629288472000 implements MigrationInterface {
+    name = 'fixChannelUserId1629288472000'
+
+    public async up(queryRunner: QueryRunner): Promise<void> {
+        await queryRunner.query(`ALTER TABLE "channel" ALTER COLUMN "userId" DROP NOT NULL;`);
+    }
+
+    public async down(queryRunner: QueryRunner): Promise<void> {
+        await queryRunner.query(`ALTER TABLE "channel" ALTER COLUMN "userId" SET NOT NULL;`);
+    }
+
+}
diff --git a/src/models/entities/channel.ts b/src/models/entities/channel.ts
index 1868f7514..f2d713612 100644
--- a/src/models/entities/channel.ts
+++ b/src/models/entities/channel.ts
@@ -23,9 +23,10 @@ export class Channel {
 	@Index()
 	@Column({
 		...id(),
+		nullable: true,
 		comment: 'The owner ID.'
 	})
-	public userId: User['id'];
+	public userId: User['id'] | null;
 
 	@ManyToOne(type => User, {
 		onDelete: 'SET NULL'
diff --git a/src/models/repositories/channel.ts b/src/models/repositories/channel.ts
index 3a6bd4c92..007b11001 100644
--- a/src/models/repositories/channel.ts
+++ b/src/models/repositories/channel.ts
@@ -90,7 +90,7 @@ export const packedChannelSchema = {
 		},
 		userId: {
 			type: 'string' as const,
-			nullable: false as const, optional: false as const,
+			nullable: true as const, optional: false as const,
 			format: 'id',
 		},
 	},