diff -u b/core/tests/Drupal/Tests/Core/DrupalKernel/DiscoverServiceProvidersTest.php b/core/tests/Drupal/Tests/Core/DrupalKernel/DiscoverServiceProvidersTest.php
--- b/core/tests/Drupal/Tests/Core/DrupalKernel/DiscoverServiceProvidersTest.php
+++ b/core/tests/Drupal/Tests/Core/DrupalKernel/DiscoverServiceProvidersTest.php
@@ -46,2 +46,14 @@
 
+  /**
+   * Tests the exception when container_yamls is not set.
+   *
+   * @covers ::discoverServiceProviders()
+   * @expectedException \Exception
+   */
+  public function testDiscoverServiceNoContainerYamls() {
+    new Settings([]);
+    $kernel = new DrupalKernel('prod', new \Composer\Autoload\ClassLoader());
+    $kernel->discoverServiceProviders();
+  }
+
 }