diff --git a/lively.server/plugins/test-runner.js b/lively.server/plugins/test-runner.js
index b55bf675c0..61ae729dbd 100644
--- a/lively.server/plugins/test-runner.js
+++ b/lively.server/plugins/test-runner.js
@@ -1,4 +1,5 @@
 import { HeadlessSession } from 'lively.headless';
+import { promise } from 'lively.lang';
 
 export default class TestRunner {
   async setup (livelyServer) {
@@ -8,35 +9,50 @@ export default class TestRunner {
   async run (module_to_test) {
     let results;
     try {
-    this.headlessSession = new HeadlessSession();
-    await this.headlessSession.open('http://localhost:9011/worlds/load?name=__newWorld__&askForWorldName=false&fastLoad=false',  (sess) => sess.runEval(`typeof $world !== 'undefined' && $world.name == 'aLivelyWorld' && $world._uiInitialized`));
-    results = await this.headlessSession.runEval(`
-    const { resource } = await System.import("lively.resources");
-    const { promise } = await System.import('lively.lang')
-    const { localInterface } = await System.import("lively-system-interface");
-    const { loadPackage } = await System.import("lively-system-interface/commands/packages.js");
-    const packageToTestLoaded = localInterface.coreInterface.getPackages().find(pkg => pkg.name === '${module_to_test}');
-    if (!packageToTestLoaded){
-      await loadPackage(localInterface.coreInterface, {
-        name: '${module_to_test}',
-        address: 'http://localhost:9011/local_projects/${module_to_test}',
-        type: 'package'
+      let attempts = 1;
+      while (true) {
+        try {
+          this.headlessSession = new HeadlessSession();
+          await this.headlessSession.open('http://localhost:9011/worlds/load?name=__newWorld__&askForWorldName=false&fastLoad=false',  (sess) => sess.runEval(`typeof $world !== 'undefined' && $world.name == 'aLivelyWorld' && $world._uiInitialized`));
+        } catch (err) {
+          if (attempts < 3) {
+            attempts++;
+            await this.headlessSession.dispose();
+            await promise.delay(1000);
+            console.log('Failed to load browser, retrying...')
+            continue;
+          }
+          else throw err;
+        }
+        break;
+      }
+      results = await this.headlessSession.runEval(`
+      const { resource } = await System.import("lively.resources");
+      const { promise } = await System.import('lively.lang')
+      const { localInterface } = await System.import("lively-system-interface");
+      const { loadPackage } = await System.import("lively-system-interface/commands/packages.js");
+      const packageToTestLoaded = localInterface.coreInterface.getPackages().find(pkg => pkg.name === '${module_to_test}');
+      if (!packageToTestLoaded){
+        await loadPackage(localInterface.coreInterface, {
+          name: '${module_to_test}',
+          address: 'http://localhost:9011/local_projects/${module_to_test}',
+          type: 'package'
+        });
+      }
+      $world.handForPointerId(1);
+      await System.import('mocha-es6/index.js');
+      await promise.waitFor(()=> !!window.chai && !!window.Mocha);
+      const { default: TestRunner } = await System.import("lively.ide/test-runner.js");
+      const runner = new TestRunner();
+      const results = await runner.runTestsInPackage('${module_to_test}');
+      results.forEach(r => {
+        r.tests?.forEach(t => {
+          if (t.error) t.error = true
+          else t.error = false;
+        })
       });
-    }
-    $world.handForPointerId(1);
-    await System.import('mocha-es6/index.js');
-    await promise.waitFor(()=> !!window.chai && !!window.Mocha);
-    const { default: TestRunner } = await System.import("lively.ide/test-runner.js");
-    const runner = new TestRunner();
-    const results = await runner.runTestsInPackage('${module_to_test}');
-    results.forEach(r => {
-      r.tests?.forEach(t => {
-        if (t.error) t.error = true
-        else t.error = false;
-      })
-    });
-    JSON.stringify(results);
-    `)
+      JSON.stringify(results);
+      `)
     } catch (err) {
       results = JSON.stringify({ error: err.message });
     } finally {