diff --git a/tests/integration/app_loader/app_loader_test.ts b/tests/integration/app_loader/app_loader_test.ts
index 4367307b8..a6fb4332c 100644
--- a/tests/integration/app_loader/app_loader_test.ts
+++ b/tests/integration/app_loader/app_loader_test.ts
@@ -16,6 +16,10 @@ import {sendInput} from '../test_case_utils.js';
 const execAsync = promisify(exec);
 const dirname = process.cwd();
 const TEST_EXECUTION_TIMEOUT = 40000;
+// Fixture hooks shell out to `npm install` and recursively delete node_modules.
+// That install/IO-bound work is far slower on a cold macOS CI runner than the
+// assertions it sets up, so it gets its own ceiling.
+const FIXTURE_SETUP_TIMEOUT = 180000;
 
 describe('App loader CLI integration', () => {
   describe.each(['app_ts', 'app_js', 'app_default'])(
@@ -29,7 +33,7 @@ describe('App loader CLI integration', () => {
 
       beforeAll(async () => {
         await execAsync('npm install', {cwd: projectPath});
-      }, TEST_EXECUTION_TIMEOUT);
+      }, FIXTURE_SETUP_TIMEOUT);
 
       it(
         'should run app via package.json start script and get responses',
@@ -62,7 +66,7 @@ describe('App loader CLI integration', () => {
         await fs
           .unlink(path.join(projectPath, 'package-lock.json'))
           .catch(() => {});
-      }, TEST_EXECUTION_TIMEOUT);
+      }, FIXTURE_SETUP_TIMEOUT);
     },
   );
 });
@@ -77,7 +81,10 @@ describe('AgentLoader discovery and loading integration', () => {
   beforeAll(async () => {
     await execAsync('npm install', {cwd: projectPath});
     loader = new AgentLoader(projectPath);
-  }, TEST_EXECUTION_TIMEOUT);
+    // Discovery is lazy; warm it here so the one-time bundling cost is charged
+    // to setup rather than to whichever test runs first.
+    await loader.preloadAgents();
+  }, FIXTURE_SETUP_TIMEOUT);
 
   it(
     'should discover apps vs agents across directories and standalone files',
@@ -138,5 +145,5 @@ describe('AgentLoader discovery and loading integration', () => {
     await fs
       .unlink(path.join(projectPath, 'package-lock.json'))
       .catch(() => {});
-  }, TEST_EXECUTION_TIMEOUT);
+  }, FIXTURE_SETUP_TIMEOUT);
 });