diff --git a/core/lib/Drupal/Core/Form/FormBuilder.php b/core/lib/Drupal/Core/Form/FormBuilder.php
index 96ecbd9..014f838 100644
--- a/core/lib/Drupal/Core/Form/FormBuilder.php
+++ b/core/lib/Drupal/Core/Form/FormBuilder.php
@@ -686,6 +686,10 @@ public function prepareForm($form_id, &$form, FormStateInterface &$form_state) {
    */
   protected function buildFormAction() {
     $request = $this->requestStack->getMasterRequest();
+    if (drupal_installation_attempted()) {
+      return $request->getRequestUri();
+    }
+
     $query = $request->query->all();
     // @todo Remove this unset() once these are removed from the request in
     //   https://www.drupal.org/node/2504709.
diff --git a/core/modules/dblog/src/Tests/DbLogFormInjectionTest.php b/core/modules/dblog/src/Tests/DbLogFormInjectionTest.php
index e622fe2..af69263 100644
--- a/core/modules/dblog/src/Tests/DbLogFormInjectionTest.php
+++ b/core/modules/dblog/src/Tests/DbLogFormInjectionTest.php
@@ -83,8 +83,10 @@ public function submitForm(array &$form, FormStateInterface $form_state) {
   protected function setUp() {
     parent::setUp();
     $this->installSchema('dblog', ['watchdog']);
-    $this->installSchema('system', ['key_value_expire', 'sequences']);
+    $this->installSchema('system', ['key_value_expire', 'router', 'sequences']);
     $this->installEntitySchema('user');
+    \Drupal::service('router.builder')->rebuild();
+
     $this->logger = \Drupal::logger('test_logger');
     $test_user = User::create(array(
       'name' => 'foobar',
diff --git a/core/modules/system/src/Tests/Form/FormDefaultHandlersTest.php b/core/modules/system/src/Tests/Form/FormDefaultHandlersTest.php
index 94187af..de3b596 100644
--- a/core/modules/system/src/Tests/Form/FormDefaultHandlersTest.php
+++ b/core/modules/system/src/Tests/Form/FormDefaultHandlersTest.php
@@ -31,7 +31,8 @@ class FormDefaultHandlersTest extends KernelTestBase implements FormInterface {
    */
   protected function setUp() {
     parent::setUp();
-    $this->installSchema('system', ['key_value_expire']);
+    $this->installSchema('system', ['key_value_expire', 'router']);
+    \Drupal::service('router.builder')->rebuild();
   }
 
   /**
diff --git a/core/modules/system/src/Tests/Form/TriggeringElementProgrammedUnitTest.php b/core/modules/system/src/Tests/Form/TriggeringElementProgrammedUnitTest.php
index ae6b82c..1684850 100644
--- a/core/modules/system/src/Tests/Form/TriggeringElementProgrammedUnitTest.php
+++ b/core/modules/system/src/Tests/Form/TriggeringElementProgrammedUnitTest.php
@@ -19,11 +19,24 @@
  */
 class TriggeringElementProgrammedUnitTest extends KernelTestBase implements FormInterface {
 
+  /**
+   * {@inheritdoc}
+   */
   public static $modules = array('system');
 
   /**
    * {@inheritdoc}
    */
+  protected function setUp() {
+    parent::setUp();
+
+    $this->installSchema('system', ['router']);
+    \Drupal::service('router.builder')->rebuild();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
   public function getFormId() {
     return 'triggering_element_programmed_form';
   }
diff --git a/core/modules/system/src/Tests/Queue/QueueSerializationTest.php b/core/modules/system/src/Tests/Queue/QueueSerializationTest.php
index 9108ac2..584d8ba 100644
--- a/core/modules/system/src/Tests/Queue/QueueSerializationTest.php
+++ b/core/modules/system/src/Tests/Queue/QueueSerializationTest.php
@@ -81,8 +81,10 @@ public function submitForm(array &$form, FormStateInterface $form_state) {
    */
   protected function setUp() {
     parent::setUp();
-    $this->installSchema('system', ['key_value_expire', 'sequences', 'queue']);
+    $this->installSchema('system', ['key_value_expire', 'router', 'sequences', 'queue']);
     $this->installEntitySchema('user');
+    \Drupal::service('router.builder')->rebuild();
+
     $this->queue = \Drupal::service('queue.database')->get('aggregator_refresh');
     $test_user = User::create(array(
       'name' => 'foobar',
diff --git a/core/modules/user/src/Tests/UserAccountFormFieldsTest.php b/core/modules/user/src/Tests/UserAccountFormFieldsTest.php
index 679eec0..0e22d19 100644
--- a/core/modules/user/src/Tests/UserAccountFormFieldsTest.php
+++ b/core/modules/user/src/Tests/UserAccountFormFieldsTest.php
@@ -26,6 +26,16 @@ class UserAccountFormFieldsTest extends KernelTestBase {
   public static $modules = array('system', 'user', 'field');
 
   /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+
+    $this->installSchema('system', ['router']);
+    \Drupal::service('router.builder')->rebuild();
+  }
+
+  /**
    * Tests the root user account form section in the "Configure site" form.
    */
   function testInstallConfigureForm() {
@@ -78,10 +88,6 @@ function testUserEditForm() {
     // Install default configuration; required for AccountFormController.
     $this->installConfig(array('user'));
 
-    // Install the router table and then rebuild.
-    $this->installSchema('system', ['router']);
-    \Drupal::service('router.builder')->rebuild();
-
     $form = $this->buildAccountForm('default');
 
     // Verify name and pass field order.