diff --git a/core/lib/Drupal/Core/Entity/Controller/EntityViewController.php b/core/lib/Drupal/Core/Entity/Controller/EntityViewController.php
index 672eed7..b9667d2 100644
--- a/core/lib/Drupal/Core/Entity/Controller/EntityViewController.php
+++ b/core/lib/Drupal/Core/Entity/Controller/EntityViewController.php
@@ -51,7 +51,8 @@ public static function create(ContainerInterface $container) {
    *   than $entity to prevent collisions with other named placeholders in the
    *   route.
    * @param string $view_mode
-   *   The view mode that should be used to display the entity.
+   *   (optional) The view mode that should be used to display the entity.
+   *   Defaults to 'full'.
    * @param string $langcode
    *   (optional) For which language the entity should be rendered, defaults to
    *   the current content language.
@@ -59,7 +60,7 @@ public static function create(ContainerInterface $container) {
    * @return array
    *   A render array as expected by drupal_render().
    */
-  public function view(EntityInterface $_entity, $view_mode, $langcode = NULL) {
+  public function view(EntityInterface $_entity, $view_mode = 'full', $langcode = NULL) {
     return $this->entityManager
       ->getRenderController($_entity->entityType())
       ->view($_entity, $view_mode, $langcode);
diff --git a/core/lib/Drupal/Core/Entity/Enhancer/EntityRouteEnhancer.php b/core/lib/Drupal/Core/Entity/Enhancer/EntityRouteEnhancer.php
index 9bc8ee4..2cf8d47 100644
--- a/core/lib/Drupal/Core/Entity/Enhancer/EntityRouteEnhancer.php
+++ b/core/lib/Drupal/Core/Entity/Enhancer/EntityRouteEnhancer.php
@@ -51,7 +51,16 @@ public function enhance(array $defaults, Request $request) {
       elseif (!empty($defaults['_entity_view'])) {
         $defaults['_controller'] = 'controller.page:content';
         $defaults['_content'] = '\Drupal\Core\Entity\Controller\EntityViewController::view';
-        list($entity_type, $view_mode) = explode('.', $defaults['_entity_view']);
+        if (strpos($defaults['_entity_view'], '.') !== FALSE) {
+          // The _entity_view entry is of the form entity_type.view_mode.
+          list($entity_type, $view_mode) = explode('.', $defaults['_entity_view']);
+          $defaults['view_mode'] = $view_mode;
+        }
+        else {
+          // Only the entity type is nominated, the view mode will use the
+          // default.
+          $entity_type = $defaults['_entity_view'];
+        }
         // Set by reference so that we get the upcast value.
         if (!empty($defaults[$entity_type])) {
           $defaults['_entity'] = &$defaults[$entity_type];
@@ -85,7 +94,6 @@ public function enhance(array $defaults, Request $request) {
             throw new \RuntimeException(sprintf('Failed to find entity of type %s in route named %s', $entity_type, $defaults[RouteObjectInterface::ROUTE_NAME]));
           }
         }
-        $defaults['view_mode'] = $view_mode;
         unset($defaults['_entity_view']);
       }
     }
diff --git a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityViewControllerTest.php b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityViewControllerTest.php
index 8c885ac..502a206 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityViewControllerTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityViewControllerTest.php
@@ -62,6 +62,10 @@ function testEntityViewController() {
       $this->drupalGet('entity-test-render-converter/' . $entity->id());
       $this->assertRaw($entity->label());
       $this->assertRaw('full');
+
+      $this->drupalGet('entity-test-render-no-view-mode/' . $entity->id());
+      $this->assertRaw($entity->label());
+      $this->assertRaw('full');
     }
   }
 }
diff --git a/core/modules/system/tests/modules/entity_test/entity_test.routing.yml b/core/modules/system/tests/modules/entity_test/entity_test.routing.yml
index 08b18fa..645fae1 100644
--- a/core/modules/system/tests/modules/entity_test/entity_test.routing.yml
+++ b/core/modules/system/tests/modules/entity_test/entity_test.routing.yml
@@ -15,3 +15,10 @@ entity_test_render_options:
     _entity_view: 'entity_test_render.full'
   requirements:
     _access: 'TRUE'
+
+entity_test_render_no_view_mode:
+  pattern: '/entity-test-render-no-view-mode/{entity_test_render}'
+  defaults:
+    _entity_view: 'entity_test_render'
+  requirements:
+    _access: 'TRUE'
diff --git a/core/tests/Drupal/Tests/Core/Entity/Enhancer/EntityRouteEnhancerTest.php b/core/tests/Drupal/Tests/Core/Entity/Enhancer/EntityRouteEnhancerTest.php
index 00dd172..9376b0a 100644
--- a/core/tests/Drupal/Tests/Core/Entity/Enhancer/EntityRouteEnhancerTest.php
+++ b/core/tests/Drupal/Tests/Core/Entity/Enhancer/EntityRouteEnhancerTest.php
@@ -66,19 +66,19 @@ public function testEnhancer() {
 
     // Set _entity_view and ensure that the entity view controller is set.
     $defaults = array();
-    $defaults['_entity_view'] = 'entity_test.default';
+    $defaults['_entity_view'] = 'entity_test.full';
     $defaults['entity_test'] = 'Mock entity';
     $defaults = $route_enhancer->enhance($defaults, $request);
     $this->assertEquals('controller.page:content', $defaults['_controller']);
     $this->assertEquals('\Drupal\Core\Entity\Controller\EntityViewController::view', $defaults['_content'], 'The entity view controller was not set.');
     $this->assertEquals($defaults['_entity'], 'Mock entity');
-    $this->assertEquals($defaults['view_mode'], 'default');
+    $this->assertEquals($defaults['view_mode'], 'full');
     $this->assertFalse(isset($defaults['_entity_view']));
 
     // Set _entity_view and ensure that the entity view controller is set using
     // a converter.
     $defaults = array();
-    $defaults['_entity_view'] = 'entity_test.default';
+    $defaults['_entity_view'] = 'entity_test.full';
     $defaults['foo'] = 'Mock entity';
     // Add a converter.
     $options['parameters']['foo'] = array('type' => 'entity:entity_test');
@@ -96,7 +96,18 @@ public function testEnhancer() {
     $this->assertEquals('controller.page:content', $defaults['_controller']);
     $this->assertEquals('\Drupal\Core\Entity\Controller\EntityViewController::view', $defaults['_content'], 'The entity view controller was not set.');
     $this->assertEquals($defaults['_entity'], 'Mock entity');
-    $this->assertEquals($defaults['view_mode'], 'default');
+    $this->assertEquals($defaults['view_mode'], 'full');
+    $this->assertFalse(isset($defaults['_entity_view']));
+
+    // Set _entity_view without a view mode.
+    $defaults = array();
+    $defaults['_entity_view'] = 'entity_test';
+    $defaults['entity_test'] = 'Mock entity';
+    $defaults = $route_enhancer->enhance($defaults, $request);
+    $this->assertEquals('controller.page:content', $defaults['_controller']);
+    $this->assertEquals('\Drupal\Core\Entity\Controller\EntityViewController::view', $defaults['_content'], 'The entity view controller was not set.');
+    $this->assertEquals($defaults['_entity'], 'Mock entity');
+    $this->assertEmpty($defaults['view_mode']);
     $this->assertFalse(isset($defaults['_entity_view']));
   }