diff --git a/core/modules/search/lib/Drupal/search/Form/SearchBlockForm.php b/core/modules/search/lib/Drupal/search/Form/SearchBlockForm.php
index bc38e5d..2da0f9e 100644
--- a/core/modules/search/lib/Drupal/search/Form/SearchBlockForm.php
+++ b/core/modules/search/lib/Drupal/search/Form/SearchBlockForm.php
@@ -66,6 +66,7 @@ public function buildForm(array $form, array &$form_state) {
 
     $route = 'search.view_' . $entity_id;
     $form['#action'] = \Drupal::url($route);
+    $form['#token'] = FALSE;
     $form['#method'] = 'get';
 
     $form['keys'] = array(
@@ -78,7 +79,12 @@ public function buildForm(array $form, array &$form_state) {
     );
 
     $form['actions'] = array('#type' => 'actions');
-    $form['actions']['submit'] = array('#type' => 'submit', '#value' => $this->t('Search'));
+    $form['actions']['submit'] = array(
+      '#type' => 'submit',
+      '#value' => $this->t('Search'),
+      // Prevent op from showing up in the query string.
+      '#name' => '',
+    );
 
     return $form;
   }
diff --git a/core/modules/search/lib/Drupal/search/Tests/SearchBlockTest.php b/core/modules/search/lib/Drupal/search/Tests/SearchBlockTest.php
index 1b96bce..d4e45db 100644
--- a/core/modules/search/lib/Drupal/search/Tests/SearchBlockTest.php
+++ b/core/modules/search/lib/Drupal/search/Tests/SearchBlockTest.php
@@ -2,7 +2,7 @@
 
 /**
  * @file
- * Definition of Drupal\search\Tests\SearchBlockTest.
+ * Contains \Drupal\search\Tests\SearchBlockTest.
  */
 
 namespace Drupal\search\Tests;
@@ -71,11 +71,14 @@ protected function testSearchFormBlock() {
     $this->assertResponse(200);
     $this->assertText('Your search yielded no results');
 
-    // Confirm that the user is redirected to the search page.
+    // Confirm that the form submits to the default search page.
+    /** @var $search_page_repository \Drupal\search\SearchPageRepositoryInterface */
+    $search_page_repository = \Drupal::service('search.search_page_repository');
+    $entity_id = $search_page_repository->getDefaultSearchPage();
     $this->assertEqual(
       $this->getUrl(),
-      url('search/node', array('query' => array('keys' => $terms['keys'], 'op' => 'Search'), 'absolute' => TRUE)),
-      'Redirected to correct url.'
+      \Drupal::url('search.view_' . $entity_id, array(), array('query' => array('keys' => $terms['keys']), 'absolute' => TRUE)),
+      'Submitted to correct url.'
     );
 
     // Test an empty search via the block form, from the front page.
@@ -88,7 +91,7 @@ protected function testSearchFormBlock() {
     // submitted empty.
     $this->assertEqual(
       $this->getUrl(),
-      url('search/node', array('query' => array('keys' => '', 'op' => 'Search'), 'absolute' => TRUE)),
+      \Drupal::url('search.view_' . $entity_id, array(), array('query' => array('keys' => ''), 'absolute' => TRUE)),
       'Redirected to correct url.'
     );
 
diff --git a/core/modules/search/lib/Drupal/search/Tests/SearchTestBase.php b/core/modules/search/lib/Drupal/search/Tests/SearchTestBase.php
index 9651064..58193a0 100644
--- a/core/modules/search/lib/Drupal/search/Tests/SearchTestBase.php
+++ b/core/modules/search/lib/Drupal/search/Tests/SearchTestBase.php
@@ -8,6 +8,7 @@
 namespace Drupal\search\Tests;
 
 use Drupal\simpletest\WebTestBase;
+use Drupal\Component\Utility\String;
 
 /**
  * Defines the common search test code.
@@ -45,7 +46,7 @@ function setUp() {
    * function parameters.
    *
    * @param string $path
-   *   Location of the form to be posted to: either a Drupal path, absolute
+   *   Location of the form to be submitted: either a Drupal path, absolute
    *   path, or NULL to use the current page.
    * @param array $edit
    *   Form field data to submit. Unlike drupalPostForm(), this does not support
diff --git a/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php b/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
index 942ebab..e7ceb44 100644
--- a/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
@@ -2152,6 +2152,8 @@ protected function handleForm(&$post, &$edit, &$upload, $submit, $form) {
         }
       }
     }
+    // An empty name means the value is not sent.
+    unset($post['']);
     return $submit_matches;
   }