diff --git a/core/lib/Drupal/Core/Url.php b/core/lib/Drupal/Core/Url.php
index 143ad1d..2abadb2 100644
--- a/core/lib/Drupal/Core/Url.php
+++ b/core/lib/Drupal/Core/Url.php
@@ -190,6 +190,10 @@ public function isExternal() {
    * @return string
    */
   public function getRouteName() {
+    if ($this->isExternal()) {
+      throw new \UnexpectedValueException('External URLs do not have an internal route name.');
+    }
+
     return $this->routeName;
   }
 
@@ -199,6 +203,10 @@ public function getRouteName() {
    * @return array
    */
   public function getRouteParameters() {
+    if ($this->isExternal()) {
+      throw new \UnexpectedValueException('External URLs do not have internal route parameters.');
+    }
+
     return $this->routeParameters;
   }
 
@@ -305,6 +313,7 @@ public function getPath() {
     if (!$this->isExternal()) {
       throw new \UnexpectedValueException('Internal URLs do not have external paths.');
     }
+
     return $this->path;
   }
 
diff --git a/core/modules/link/lib/Drupal/link/Plugin/Field/FieldType/LinkItem.php b/core/modules/link/lib/Drupal/link/Plugin/Field/FieldType/LinkItem.php
index 1afa70e..4bf0b63 100644
--- a/core/modules/link/lib/Drupal/link/Plugin/Field/FieldType/LinkItem.php
+++ b/core/modules/link/lib/Drupal/link/Plugin/Field/FieldType/LinkItem.php
@@ -20,7 +20,7 @@
  * @FieldType(
  *   id = "link",
  *   label = @Translation("Link"),
- *   description = @Translation("Stores a URL string, optional varchar link text, and optional blob of options to assemble a link."),
+ *   description = @Translation("Stores a URL string for external links or route name and parameters for internal links, an optional varchar link text and an optional blob of options to assemble a link."),
  *   instance_settings = {
  *     "url_type" = \Drupal\link\LinkItemInterface::LINK_GENERIC,
  *     "title" = "1"
@@ -106,9 +106,9 @@ public function instanceSettingsForm(array $form, array &$form_state) {
       '#title' => t('Allowed url type'),
       '#default_value' => $this->getSetting('url_type'),
       '#options' => array(
-        static::LINK_INTERNAL => t('Internal urls only'),
-        static::LINK_EXTERNAL => t('External urls only'),
-        static::LINK_GENERIC => t('Both internal and external urls'),
+        static::LINK_INTERNAL => t('Internal URLs only'),
+        static::LINK_EXTERNAL => t('External URLs only'),
+        static::LINK_GENERIC => t('Both internal and external URLs'),
       ),
     );
 
diff --git a/core/modules/link/lib/Drupal/link/Plugin/Field/FieldWidget/LinkWidget.php b/core/modules/link/lib/Drupal/link/Plugin/Field/FieldWidget/LinkWidget.php
index 9dfd710..e54159f 100644
--- a/core/modules/link/lib/Drupal/link/Plugin/Field/FieldWidget/LinkWidget.php
+++ b/core/modules/link/lib/Drupal/link/Plugin/Field/FieldWidget/LinkWidget.php
@@ -178,7 +178,7 @@ public function validateUrl(&$element, &$form_state, $form) {
     $url_is_valid = TRUE;
 
     // Validate only if the field type supports internal URLs.
-    if ($element['url']['#value'] !== '' && $url_type & LinkItemInterface::LINK_INTERNAL) {
+    if ($element['url']['#value'] !== '') {
       try {
         $url = Url::createFromPath($element['url']['#value']);
 
diff --git a/core/tests/Drupal/Tests/Core/ExternalUrlTest.php b/core/tests/Drupal/Tests/Core/ExternalUrlTest.php
index f355b97..37f1a40 100644
--- a/core/tests/Drupal/Tests/Core/ExternalUrlTest.php
+++ b/core/tests/Drupal/Tests/Core/ExternalUrlTest.php
@@ -153,10 +153,12 @@ public function testToArray(Url $url) {
    *
    * @depends testCreateFromPath
    *
+   * @expectedException \UnexpectedValueException
+   *
    * @covers ::getRouteName()
    */
   public function testGetRouteName(Url $url) {
-    $this->assertSame(NULL, $url->getRouteName());
+    $url->getRouteName();
   }
 
   /**
@@ -164,10 +166,12 @@ public function testGetRouteName(Url $url) {
    *
    * @depends testCreateFromPath
    *
+   * @expectedException \UnexpectedValueException
+   *
    * @covers ::getRouteParameters()
    */
   public function testGetRouteParameters(Url $url) {
-    $this->assertSame(array(), $url->getRouteParameters());
+    $url->getRouteParameters();
   }
 
   /**