diff --git a/core/lib/Drupal/Core/Form/FormBuilder.php b/core/lib/Drupal/Core/Form/FormBuilder.php
index d3eabe2db8a..d2040505722 100644
--- a/core/lib/Drupal/Core/Form/FormBuilder.php
+++ b/core/lib/Drupal/Core/Form/FormBuilder.php
@@ -533,6 +533,11 @@ class FormBuilder implements FormBuilderInterface, FormValidatorInterface, FormS
 
     $form['#type'] = 'form';
 
+    // Only update the action if it is not already set.
+    if (!isset($form['#action'])) {
+      $form['#action'] = $this->requestUri();
+    }
+
     // Fix the form method, if it is 'get' in $form_state, but not in $form.
     if ($form_state->isMethodType('get') && !isset($form['#method'])) {
       $form['#method'] = 'get';
@@ -1096,4 +1101,13 @@ class FormBuilder implements FormBuilderInterface, FormValidatorInterface, FormS
     return $this->currentUser;
   }
 
+  /**
+   * Gets the current request URI.
+   *
+   * @return string
+   */
+  protected function requestUri() {
+    return request_uri();
+  }
+
 }
diff --git a/core/lib/Drupal/Core/Render/Element/Form.php b/core/lib/Drupal/Core/Render/Element/Form.php
index 2dbd1c77c67..3b3864607d9 100644
--- a/core/lib/Drupal/Core/Render/Element/Form.php
+++ b/core/lib/Drupal/Core/Render/Element/Form.php
@@ -22,7 +22,6 @@ class Form extends RenderElement {
   public function getInfo() {
     return array(
       '#method' => 'post',
-      '#action' => request_uri(),
       '#theme_wrappers' => array('form'),
     );
   }
diff --git a/core/lib/Drupal/Core/Render/ElementInfoManager.php b/core/lib/Drupal/Core/Render/ElementInfoManager.php
index 784fdef1473..1054b85285d 100644
--- a/core/lib/Drupal/Core/Render/ElementInfoManager.php
+++ b/core/lib/Drupal/Core/Render/ElementInfoManager.php
@@ -7,6 +7,7 @@
 
 namespace Drupal\Core\Render;
 
+use Drupal\Core\Cache\Cache;
 use Drupal\Core\Cache\CacheBackendInterface;
 use Drupal\Core\Extension\ModuleHandlerInterface;
 use Drupal\Core\Plugin\DefaultPluginManager;
@@ -65,6 +66,12 @@ class ElementInfoManager extends DefaultPluginManager implements ElementInfoMana
    * Builds up all element information.
    */
   protected function buildInfo() {
+    // Get cached definitions.
+    if ($cache = $this->cacheBackend->get('element_info_build')) {
+      return $cache->data;
+    }
+
+    // Otherwise, rebuild and cache.
     // @todo Remove this hook once all elements are converted to plugins in
     //   https://www.drupal.org/node/2311393.
     $info = $this->moduleHandler->invokeAll('element_info');
@@ -81,12 +88,15 @@ class ElementInfoManager extends DefaultPluginManager implements ElementInfoMana
       }
       $info[$element_type] = $element_info;
     }
+
     foreach ($info as $element_type => $element) {
       $info[$element_type]['#type'] = $element_type;
     }
     // Allow modules to alter the element type defaults.
     $this->moduleHandler->alter('element_info', $info);
 
+    $this->cacheBackend->set('element_info_build', $info, Cache::PERMANENT);
+
     return $info;
   }
 
@@ -99,4 +109,15 @@ class ElementInfoManager extends DefaultPluginManager implements ElementInfoMana
     return parent::createInstance($plugin_id, $configuration);
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function clearCachedDefinitions() {
+    $this->elementInfo = NULL;
+    $this->cacheBackend->delete('element_info_build');
+
+    parent::clearCachedDefinitions();
+  }
+
+
 }
diff --git a/core/tests/Drupal/Tests/Core/Form/FormTestBase.php b/core/tests/Drupal/Tests/Core/Form/FormTestBase.php
index 61c4f95bbef..13eae9ab82a 100644
--- a/core/tests/Drupal/Tests/Core/Form/FormTestBase.php
+++ b/core/tests/Drupal/Tests/Core/Form/FormTestBase.php
@@ -327,6 +327,13 @@ class TestFormBuilder extends FormBuilder {
     static::$seenIds = array();
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  protected function requestUri() {
+    return '';
+  }
+
 }
 
 }
diff --git a/core/tests/Drupal/Tests/Core/Render/ElementInfoManagerTest.php b/core/tests/Drupal/Tests/Core/Render/ElementInfoManagerTest.php
index 42c9f3babbb..ef9a9569a58 100644
--- a/core/tests/Drupal/Tests/Core/Render/ElementInfoManagerTest.php
+++ b/core/tests/Drupal/Tests/Core/Render/ElementInfoManagerTest.php
@@ -69,6 +69,21 @@ class ElementInfoManagerTest extends UnitTestCase {
         return $info;
       }));
 
+    $this->cache->expects($this->at(0))
+      ->method('get')
+      ->with('element_info_build')
+      ->will($this->returnValue(FALSE));
+    $this->cache->expects($this->at(1))
+      ->method('get')
+      ->with('element_info')
+      ->will($this->returnValue(FALSE));
+    $this->cache->expects($this->at(2))
+      ->method('set')
+      ->with('element_info');
+    $this->cache->expects($this->at(3))
+      ->method('set')
+      ->with('element_info_build');
+
     $this->assertEquals($expected_info, $this->elementInfo->getInfo($type));
   }