diff --git a/packages/backend/package.json b/packages/backend/package.json
index 8680610441b3..eaad96d5f6ee 100644
--- a/packages/backend/package.json
+++ b/packages/backend/package.json
@@ -19,7 +19,7 @@
 		"watch": "node watch.mjs",
 		"restart": "pnpm build && pnpm start",
 		"dev": "nodemon -w src -e ts,js,mjs,cjs,json --exec \"cross-env NODE_ENV=development pnpm run restart\"",
-		"typecheck": "tsc --noEmit",
+		"typecheck": "tsc --noEmit && tsc -p test --noEmit",
 		"eslint": "eslint --quiet \"src/**/*.ts\"",
 		"lint": "pnpm typecheck && pnpm eslint",
 		"jest": "cross-env NODE_ENV=test node --experimental-vm-modules --experimental-import-meta-resolve node_modules/jest/bin/jest.js --forceExit --config jest.config.unit.cjs",
diff --git a/packages/backend/test/e2e/note.ts b/packages/backend/test/e2e/note.ts
index 973bcbd750cf..11016f58aef3 100644
--- a/packages/backend/test/e2e/note.ts
+++ b/packages/backend/test/e2e/note.ts
@@ -472,7 +472,7 @@ describe('Note', () => {
 						priority: 0,
 						value: true,
 					},
-				},
+				} as any,
 			}, alice);
 
 			assert.strictEqual(res.status, 200);
@@ -784,7 +784,7 @@ describe('Note', () => {
 						priority: 1,
 						value: 0,
 					},
-				},
+				} as any,
 			}, alice);
 
 			assert.strictEqual(res.status, 200);
@@ -838,7 +838,7 @@ describe('Note', () => {
 						priority: 1,
 						value: 0,
 					},
-				},
+				} as any,
 			}, alice);
 
 			assert.strictEqual(res.status, 200);
@@ -894,7 +894,7 @@ describe('Note', () => {
 						priority: 1,
 						value: 1,
 					},
-				},
+				} as any,
 			}, alice);
 
 			assert.strictEqual(res.status, 200);
diff --git a/packages/backend/test/e2e/timelines.ts b/packages/backend/test/e2e/timelines.ts
index d413703edeee..5487292afcd5 100644
--- a/packages/backend/test/e2e/timelines.ts
+++ b/packages/backend/test/e2e/timelines.ts
@@ -890,17 +890,35 @@ describe('Timelines', () => {
 
 			const list = await api('users/lists/create', { name: 'list' }, alice).then(res => res.body);
 			await api('users/lists/push', { listId: list.id, userId: bob.id }, alice);
+			await api('users/lists/update-membership', { listId: list.id, userId: bob.id, withReplies: false }, alice);
 			await sleep(1000);
 			const aliceNote = await post(alice, { text: 'hi' });
 			const bobNote = await post(bob, { text: 'hi', replyId: aliceNote.id });
 
 			await waitForPushToTl();
 
-			const res = await api('notes/user-list-timeline', { listId: list.id, withReplies: false }, alice);
+			const res = await api('notes/user-list-timeline', { listId: list.id }, alice);
 
 			assert.strictEqual(res.body.some((note: any) => note.id === bobNote.id), true);
 		});
 
+		test.concurrent('withReplies: false でリスインしているフォローしていないユーザーの他人への返信が含まれない', async () => {
+			const [alice, bob, carol] = await Promise.all([signup(), signup(), signup()]);
+
+			const list = await api('users/lists/create', { name: 'list' }, alice).then(res => res.body);
+			await api('users/lists/push', { listId: list.id, userId: bob.id }, alice);
+			await api('users/lists/update-membership', { listId: list.id, userId: bob.id, withReplies: false }, alice);
+			await sleep(1000);
+			const carolNote = await post(carol, { text: 'hi' });
+			const bobNote = await post(bob, { text: 'hi', replyId: carolNote.id });
+
+			await waitForPushToTl();
+
+			const res = await api('notes/user-list-timeline', { listId: list.id }, alice);
+
+			assert.strictEqual(res.body.some((note: any) => note.id === bobNote.id), false);
+		});
+
 		test.concurrent('withReplies: true でリスインしているフォローしていないユーザーの他人への返信が含まれる', async () => {
 			const [alice, bob, carol] = await Promise.all([signup(), signup(), signup()]);
 
diff --git a/packages/backend/test/global.d.ts b/packages/backend/test/global.d.ts
new file mode 100644
index 000000000000..0363073356ce
--- /dev/null
+++ b/packages/backend/test/global.d.ts
@@ -0,0 +1,7 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+type FIXME = any;
diff --git a/packages/backend/test/prelude/get-api-validator.ts b/packages/backend/test/prelude/get-api-validator.ts
index b86a7a978def..7aa7a92702d8 100644
--- a/packages/backend/test/prelude/get-api-validator.ts
+++ b/packages/backend/test/prelude/get-api-validator.ts
@@ -4,10 +4,10 @@
  */
 
 import Ajv from 'ajv';
-import { Schema } from '@/misc/schema';
+import { Schema } from '@/misc/json-schema.js';
 
 export const getValidator = (paramDef: Schema) => {
-	const ajv = new Ajv({
+	const ajv = new Ajv.default({
 		useDefaults: true,
 	});
 	ajv.addFormat('misskey:id', /^[a-zA-Z0-9]+$/);
diff --git a/packages/backend/test/tsconfig.json b/packages/backend/test/tsconfig.json
index 4597ff87803e..2b562acda81a 100644
--- a/packages/backend/test/tsconfig.json
+++ b/packages/backend/test/tsconfig.json
@@ -5,7 +5,7 @@
 		"noImplicitAny": true,
 		"noImplicitReturns": true,
 		"noUnusedParameters": false,
-		"noUnusedLocals": true,
+		"noUnusedLocals": false,
 		"noFallthroughCasesInSwitch": true,
 		"declaration": false,
 		"sourceMap": true,
@@ -18,6 +18,7 @@
 		"strict": true,
 		"strictNullChecks": true,
 		"strictPropertyInitialization": false,
+		"skipLibCheck": true,
 		"experimentalDecorators": true,
 		"emitDecoratorMetadata": true,
 		"resolveJsonModule": true,
diff --git a/packages/backend/test/unit/RelayService.ts b/packages/backend/test/unit/RelayService.ts
index f2a67dba46b4..9676abf07b74 100644
--- a/packages/backend/test/unit/RelayService.ts
+++ b/packages/backend/test/unit/RelayService.ts
@@ -90,7 +90,8 @@ describe('RelayService', () => {
 
 		expect(queueService.deliver).toHaveBeenCalled();
 		expect(queueService.deliver.mock.lastCall![1]?.type).toBe('Undo');
-		expect(queueService.deliver.mock.lastCall![1]?.object.type).toBe('Follow');
+		expect(typeof queueService.deliver.mock.lastCall![1]?.object).toBe('object');
+		expect((queueService.deliver.mock.lastCall![1]?.object as any).type).toBe('Follow');
 		expect(queueService.deliver.mock.lastCall![2]).toBe('https://example.com');
 		//expect(queueService.deliver.mock.lastCall![0].username).toBe('relay.actor');