diff --git a/core/modules/link/src/Plugin/Field/FieldType/LinkItem.php b/core/modules/link/src/Plugin/Field/FieldType/LinkItem.php
index 0b1709b..4c0467c 100644
--- a/core/modules/link/src/Plugin/Field/FieldType/LinkItem.php
+++ b/core/modules/link/src/Plugin/Field/FieldType/LinkItem.php
@@ -177,20 +177,21 @@ public function getUrl() {
    * {@inheritdoc}
    */
   public function setValue($values, $notify = TRUE) {
-    // The main property for LinkItem is uri so if value is not array then it
-    // should be a uri.
+    // Treat the values as property value of the main property, if no array is
+    // given.
     if (isset($values) && !is_array($values)) {
-      $values = ['uri' => $values];
+      $values = [static::mainPropertyName() => $values];
+    }
+    if (isset($values)) {
+      $values += [
+        'options' => [],
+      ];
     }
-    $values += [
-      'title' => NULL,
-      'options' => [],
-    ];
     // Unserialize the values.
     // @todo The storage controller should take care of this, see
     //   SqlContentEntityStorage::loadFieldItems, see
     //   https://www.drupal.org/node/2414835
-    if (isset($values['options']) && is_string($values['options'])) {
+    if (is_string($values['options'])) {
       $values['options'] = unserialize($values['options']);
     }
     parent::setValue($values, $notify);
diff --git a/core/modules/link/src/Tests/LinkItemTest.php b/core/modules/link/src/Tests/LinkItemTest.php
index 352d909..a476853 100644
--- a/core/modules/link/src/Tests/LinkItemTest.php
+++ b/core/modules/link/src/Tests/LinkItemTest.php
@@ -101,20 +101,40 @@ public function testLinkItem() {
     $this->assertEqual($entity->field_test->title, $new_title);
     $this->assertEqual($entity->field_test->options['attributes']['class'], $new_class);
 
-    // Test the generateSampleValue() method.
-    $entity = entity_create('entity_test');
-    $entity->field_test->generateSampleItems();
-    $this->entityValidateAndSave($entity);
-
+    // Check that if we only set uri the default values for title and options
+    // are also initialized.
     $entity->field_test = ['uri' => 'internal:/node/add'];
     $this->assertEqual($entity->field_test->uri, 'internal:/node/add');
     $this->assertNull($entity->field_test->title);
     $this->assertIdentical($entity->field_test->options, []);
 
+    // Check that if set uri and serialize options then the default values are
+    // properly initialized.
+    $entity->field_test = [
+      'uri' => 'internal:/node/add',
+      'options' => serialize(['query' => NULL]),
+    ];
+    $this->assertEqual($entity->field_test->uri, 'internal:/node/add');
+    $this->assertNull($entity->field_test->title);
+    $this->assertNull($entity->field_test->options['query']);
+
+    // Check that if we set the direct value of link field it correctly set the
+    // uri and the default values of the field.
     $entity->field_test = 'internal:/node/add';
     $this->assertEqual($entity->field_test->uri, 'internal:/node/add');
     $this->assertNull($entity->field_test->title);
     $this->assertIdentical($entity->field_test->options, []);
+
+    // Check that setting LinkItem value NULL doesn't generate any error or
+    // warning.
+    $entity->field_test[0] = NULL;
+    $this->assertNull($entity->field_test[0]->getValue());
+
+
+    // Test the generateSampleValue() method.
+    $entity = entity_create('entity_test');
+    $entity->field_test->generateSampleItems();
+    $this->entityValidateAndSave($entity);
   }
 
 }