diff --git a/core/modules/language/migration_templates/d6_language_negotiation_settings.yml b/core/modules/language/migration_templates/d6_language_negotiation_settings.yml
index bc5c133..abc71f6 100644
--- a/core/modules/language/migration_templates/d6_language_negotiation_settings.yml
+++ b/core/modules/language/migration_templates/d6_language_negotiation_settings.yml
@@ -16,6 +16,7 @@ process:
   url/source:
     plugin: static_map
     source: language_negotiation
+    default_value: path_prefix
     map:
       # LANGUAGE_NEGOTIATION_NONE = 0
       # LANGUAGE_NEGOTIATION_PATH_DEFAULT = 1
@@ -28,3 +29,6 @@ process:
 destination:
   plugin: config
   config_name: language.negotiation
+migration_dependencies:
+  required:
+    - language
diff --git a/core/modules/language/migration_templates/d6_language_prefixes_and_domains.yml b/core/modules/language/migration_templates/d6_language_prefixes_and_domains.yml
deleted file mode 100644
index efafafb..0000000
--- a/core/modules/language/migration_templates/d6_language_prefixes_and_domains.yml
+++ /dev/null
@@ -1,25 +0,0 @@
-id: d6_language_prefixes_and_domains
-label: Language prefixes and domains
-migration_tags:
-  - Drupal 6
-source:
-  plugin: language
-  fetch_all: true
-  negotiation: true
-process:
-  url/prefixes:
-    plugin: array_build
-    source: languages
-    key: language
-    value: prefix
-  url/domains:
-    plugin: language_domains
-    source: languages
-    key: language
-    value: domain
-destination:
-  plugin: config
-  config_name: language.negotiation
-migration_dependencies:
-  required:
-    - language
diff --git a/core/modules/language/migration_templates/d7_language_negotiation_settings.yml b/core/modules/language/migration_templates/d7_language_negotiation_settings.yml
index f03be78..7759965 100644
--- a/core/modules/language/migration_templates/d7_language_negotiation_settings.yml
+++ b/core/modules/language/migration_templates/d7_language_negotiation_settings.yml
@@ -8,8 +8,25 @@ source:
     - locale_language_negotiation_session_param
     - locale_language_negotiation_url_part
 process:
-  'session/parameter': locale_language_negotiation_session_param
-  'url/source': locale_language_negotiation_url_part
+  session/parameter:
+    plugin: default_value
+    source: locale_language_negotiation_session_param
+    default_value: 'language'
+  selected_langcode:
+    plugin: default_value
+    default_value: 'site_default'
+  url/source:
+    plugin: static_map
+    source: locale_language_negotiation_url_part
+    default_value: path_prefix
+    map:
+      # LOCALE_LANGUAGE_NEGOTIATION_URL_PREFIX = 0
+      # LOCALE_LANGUAGE_NEGOTIATION_URL_DOMAIN = 1
+      0: path_prefix
+      1: domain
 destination:
   plugin: config
   config_name: language.negotiation
+migration_dependencies:
+  required:
+    - language
diff --git a/core/modules/language/migration_templates/language_prefixes_and_domains.yml b/core/modules/language/migration_templates/language_prefixes_and_domains.yml
new file mode 100644
index 0000000..edc5b54
--- /dev/null
+++ b/core/modules/language/migration_templates/language_prefixes_and_domains.yml
@@ -0,0 +1,26 @@
+id: language_prefixes_and_domains
+label: Language prefixes and domains
+migration_tags:
+  - Drupal 6
+  - Drupal 7
+source:
+  plugin: language
+  fetch_all: true
+  domain_negotiation: true
+process:
+  url/prefixes:
+    plugin: array_build
+    source: languages
+    key: language
+    value: prefix
+  url/domains:
+    plugin: language_domains
+    source: languages
+    key: language
+    value: domain
+destination:
+  plugin: config
+  config_name: language.negotiation
+migration_dependencies:
+  required:
+    - language
diff --git a/core/modules/language/src/Plugin/migrate/process/LanguageDomains.php b/core/modules/language/src/Plugin/migrate/process/LanguageDomains.php
index 8e38a95..b800fb4 100644
--- a/core/modules/language/src/Plugin/migrate/process/LanguageDomains.php
+++ b/core/modules/language/src/Plugin/migrate/process/LanguageDomains.php
@@ -21,21 +21,20 @@ class LanguageDomains extends ArrayBuild {
    * {@inheritdoc}
    */
   public function transform($value, MigrateExecutableInterface $migrate_executable, Row $row, $destination_property) {
-    if ($row->hasSourceProperty('negotiation')) {
-      // Check if domain negotiation is used (LANGUAGE_NEGOTIATION_DOMAIN = 3).
-      if ($row->getSourceProperty('negotiation') == '3') {
-        global $base_url;
+    if ($row->getSourceProperty('domain_negotiation')) {
+      global $base_url;
 
-        foreach ($value as $old_key => $old_value) {
-          if (empty($old_value['domain'])) {
-            // The default language domain might be empty.
-            // If it is, use the current domain.
-            $value[$old_key]['domain'] = parse_url($base_url, PHP_URL_HOST);
-          }
-          else {
-            // Only keep the host part of the domain.
-            $value[$old_key]['domain'] = parse_url($old_value['domain'], PHP_URL_HOST);
-          }
+      foreach ($value as $old_key => $old_value) {
+        if (empty($old_value['domain'])) {
+          // The default language domain might be empty.
+          // If it is, use the current domain.
+          $value[$old_key]['domain'] = parse_url($base_url, PHP_URL_HOST);
+        }
+        else {
+          // Ensure we have a protocol when checking for the hostname.
+          $domain = 'http://' . str_replace(['http://', 'https://'], '', $old_value['domain']);
+          // Only keep the host part of the domain.
+          $value[$old_key]['domain'] = parse_url($domain, PHP_URL_HOST);
         }
       }
     }
diff --git a/core/modules/language/src/Plugin/migrate/source/Language.php b/core/modules/language/src/Plugin/migrate/source/Language.php
index 236d2fe..8543a94 100644
--- a/core/modules/language/src/Plugin/migrate/source/Language.php
+++ b/core/modules/language/src/Plugin/migrate/source/Language.php
@@ -60,12 +60,14 @@ public function prepareRow(Row $row) {
       $row->setSourceProperty('languages', $languages);
     }
 
-    if (!empty($this->configuration['negotiation'])) {
-      // Get the language negotiation method.
-      // We need it to find out if domain negotiation is used and thus fill in
-      // the default language domain, which may be empty.
-      $negotiation = $this->variableGet('language_negotiation', 0);
-      $row->setSourceProperty('negotiation', $negotiation);
+    if (!empty($this->configuration['domain_negotiation'])) {
+      // Check if domain negotiation is used to be able to fill in the default
+      // language domain, which may be empty. In D6, domain negotiation is used
+      // when the 'language_negotiation' variable is set to '3', and in D7, when
+      // the 'locale_language_negotiation_url_part' variable is set to '1'.
+      if ($this->variableGet('language_negotiation', 0) == 3 || $this->variableGet('locale_language_negotiation_url_part', 0) == 1) {
+        $row->setSourceProperty('domain_negotiation', TRUE);
+      }
     }
 
     return parent::prepareRow($row);
diff --git a/core/modules/language/tests/src/Kernel/Migrate/d6/MigrateLanguageNegotiationSettingsTest.php b/core/modules/language/tests/src/Kernel/Migrate/d6/MigrateLanguageNegotiationSettingsTest.php
index 7e60e25..0e74f49 100644
--- a/core/modules/language/tests/src/Kernel/Migrate/d6/MigrateLanguageNegotiationSettingsTest.php
+++ b/core/modules/language/tests/src/Kernel/Migrate/d6/MigrateLanguageNegotiationSettingsTest.php
@@ -24,7 +24,7 @@ public function testLanguageNegotiationWithDefaultPathPrefix() {
     $this->executeMigrations([
       'language',
       'd6_language_negotiation_settings',
-      'd6_language_prefixes_and_domains',
+      'language_prefixes_and_domains',
       'd6_language_types',
     ]);
 
@@ -63,7 +63,7 @@ public function testLanguageNegotiationWithNoNegotiation() {
     $this->executeMigrations([
       'language',
       'd6_language_negotiation_settings',
-      'd6_language_prefixes_and_domains',
+      'language_prefixes_and_domains',
       'd6_language_types',
     ]);
 
@@ -95,7 +95,7 @@ public function testLanguageNegotiationWithPathPrefix() {
     $this->executeMigrations([
       'language',
       'd6_language_negotiation_settings',
-      'd6_language_prefixes_and_domains',
+      'language_prefixes_and_domains',
       'd6_language_types',
     ]);
 
@@ -136,7 +136,7 @@ public function testLanguageNegotiationWithDomain() {
     $this->executeMigrations([
       'language',
       'd6_language_negotiation_settings',
-      'd6_language_prefixes_and_domains',
+      'language_prefixes_and_domains',
       'd6_language_types',
     ]);
 
diff --git a/core/modules/language/tests/src/Unit/process/LanguageDomainsTest.php b/core/modules/language/tests/src/Unit/process/LanguageDomainsTest.php
new file mode 100644
index 0000000..720f02b
--- /dev/null
+++ b/core/modules/language/tests/src/Unit/process/LanguageDomainsTest.php
@@ -0,0 +1,59 @@
+<?php
+
+namespace Drupal\Tests\language\Unit\process;
+
+use Drupal\language\Plugin\migrate\process\LanguageDomains;
+use Drupal\Tests\migrate\Unit\process\MigrateProcessTestCase;
+
+/**
+ * @coversDefaultClass \Drupal\language\Plugin\migrate\process\LanguageDomains
+ * @group language
+ */
+class LanguageDomainsTest extends MigrateProcessTestCase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $backupGlobalsBlacklist = ['base_url'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    $configuration = [
+      'key' => 'language',
+      'value' => 'domain',
+    ];
+    $this->plugin = new LanguageDomains($configuration, 'map', []);
+    parent::setUp();
+
+    // The language_domains plugin calls getSourceProperty() to check if domain
+    // negotiation is used. If it is the values will be processed so we need it
+    // to return TRUE to be able to test the process.
+    $this->row->expects($this->once())
+      ->method('getSourceProperty')
+      ->will($this->returnValue(TRUE));
+
+    // The language_domains plugin use $base_url to fill empty domains.
+    global $base_url;
+    $base_url = 'http://example.com';
+  }
+
+  public function testTransform() {
+    $source = [
+      ['language' => 'en', 'domain' => ''],
+      ['language' => 'fr', 'domain' => 'fr.example.com'],
+      ['language' => 'es', 'domain' => 'http://es.example.com'],
+      ['language' => 'hu', 'domain' => 'https://hu.example.com'],
+    ];
+    $expected = [
+      'en' => 'example.com',
+      'fr' => 'fr.example.com',
+      'es' => 'es.example.com',
+      'hu' => 'hu.example.com',
+    ];
+    $value = $this->plugin->transform($source, $this->migrateExecutable, $this->row, 'destinationproperty');
+    $this->assertSame($value, $expected);
+  }
+
+}
diff --git a/core/modules/migrate_drupal_ui/src/Form/MigrateUpgradeForm.php b/core/modules/migrate_drupal_ui/src/Form/MigrateUpgradeForm.php
index 76e7c3e..b9d3ad3 100644
--- a/core/modules/migrate_drupal_ui/src/Form/MigrateUpgradeForm.php
+++ b/core/modules/migrate_drupal_ui/src/Form/MigrateUpgradeForm.php
@@ -286,7 +286,7 @@ class MigrateUpgradeForm extends ConfirmFormBase {
       'source_module' => 'locale',
       'destination_module' => 'language',
     ],
-    'd6_language_prefixes_and_domains' => [
+    'language_prefixes_and_domains' => [
       'source_module' => 'locale',
       'destination_module' => 'language',
     ],