diff --git a/core/modules/system/src/Tests/DrupalKernel/ContainerRebuildWebTest.php b/core/modules/system/src/Tests/DrupalKernel/ContainerRebuildWebTest.php
index a9c0c91..36ed68f 100644
--- a/core/modules/system/src/Tests/DrupalKernel/ContainerRebuildWebTest.php
+++ b/core/modules/system/src/Tests/DrupalKernel/ContainerRebuildWebTest.php
@@ -47,7 +47,6 @@ public function testContainerInvalidation() {
     // Ensure that after setting the parameter, without a container rebuild the
     // parameter is still not set.
     $this->writeSettings(['settings' => ['container_rebuild_test_parameter' => (object) ['value' => 'rebuild_me_please', 'required' => TRUE]]]);
-    sleep(5);
 
     $this->drupalGet('<front>');
     $this->assertHeader('container_rebuild_test_parameter', FALSE);