diff --git a/packages/backend/jest.config.cjs b/packages/backend/jest.config.cjs
index 1552fa3620..5a4aa4e15a 100644
--- a/packages/backend/jest.config.cjs
+++ b/packages/backend/jest.config.cjs
@@ -216,5 +216,5 @@ module.exports = {
 	logHeapUsage: true, // To debug when out-of-memory happens on CI
 	workerIdleMemoryLimit: '1GiB', // Limit the worker to 1GB (GitHub Workflows dies at 2GB)
 
-	maxConcurrency: 8,
+	maxConcurrency: 32,
 };
diff --git a/packages/backend/test/e2e/timelines.ts b/packages/backend/test/e2e/timelines.ts
index 540b866b28..fce1eacf00 100644
--- a/packages/backend/test/e2e/timelines.ts
+++ b/packages/backend/test/e2e/timelines.ts
@@ -378,7 +378,7 @@ describe('Timelines', () => {
 			assert.strictEqual(res.body.some(note => note.id === bobNote2.id), true);
 			assert.strictEqual(res.body.some(note => note.id === carolNote1.id), false);
 			assert.strictEqual(res.body.some(note => note.id === carolNote2.id), false);
-		}, 1000 * 10);
+		});
 
 		test.concurrent('フォローしているユーザーのチャンネル投稿が含まれない', async () => {
 			const [alice, bob] = await Promise.all([signup(), signup()]);
@@ -672,7 +672,7 @@ describe('Timelines', () => {
 
 			assert.strictEqual(res.body.some(note => note.id === bobNote1.id), false);
 			assert.strictEqual(res.body.some(note => note.id === bobNote2.id), true);
-		}, 1000 * 10);
+		});
 	});
 
 	describe('Social TL', () => {
@@ -812,7 +812,7 @@ describe('Timelines', () => {
 
 			assert.strictEqual(res.body.some(note => note.id === bobNote1.id), false);
 			assert.strictEqual(res.body.some(note => note.id === bobNote2.id), true);
-		}, 1000 * 10);
+		});
 	});
 
 	describe('User List TL', () => {
@@ -1025,7 +1025,7 @@ describe('Timelines', () => {
 
 			assert.strictEqual(res.body.some(note => note.id === bobNote1.id), false);
 			assert.strictEqual(res.body.some(note => note.id === bobNote2.id), true);
-		}, 1000 * 10);
+		});
 
 		test.concurrent('リスインしているユーザーの自身宛ての visibility: specified なノートが含まれる', async () => {
 			const [alice, bob] = await Promise.all([signup(), signup()]);
@@ -1184,7 +1184,7 @@ describe('Timelines', () => {
 
 			assert.strictEqual(res.body.some(note => note.id === bobNote1.id), false);
 			assert.strictEqual(res.body.some(note => note.id === bobNote2.id), true);
-		}, 1000 * 10);
+		});
 
 		test.concurrent('[withChannelNotes: true] チャンネル投稿が含まれる', async () => {
 			const [alice, bob] = await Promise.all([signup(), signup()]);