--- /dev/null
+<?php
+
+namespace Drupal\Tests\language\Functional;
+
+use Drupal\Tests\BrowserTestBase;
+
+/**
+ * Confirm that paths are not changed on monolingual non-English sites.
+ *
+ * @group language
+ */
+class LanguagePathMonolingualTest extends BrowserTestBase {
+
+ /**
+ * Modules to enable.
+ *
+ * @var array
+ */
+ public static $modules = ['block', 'language', 'path'];
+
+ protected function setUp() {
+ parent::setUp();
+
+ // Create and log in user.
+ $web_user = $this->drupalCreateUser(['administer languages', 'access administration pages', 'administer site configuration']);
+ $this->drupalLogin($web_user);
+
+ // Enable French language.
+ $edit = [];
+ $edit['predefined_langcode'] = 'fr';
+ $this->drupalPostForm('admin/config/regional/language/add', $edit, t('Add language'));
+
+ // Make French the default language.
+ $edit = [
+ 'site_default_language' => 'fr',
+ ];
+ $this->drupalPostForm('admin/config/regional/language', $edit, t('Save configuration'));
+
+ // Delete English.
+ $this->drupalPostForm('admin/config/regional/language/delete/en', [], t('Delete'));
+
+ // Changing the default language causes a container rebuild. Therefore need
+ // to rebuild the container in the test environment.
+ $this->rebuildContainer();
+
+ // Verify that French is the only language.
+ $this->container->get('language_manager')->reset();
+ $this->assertFalse(\Drupal::languageManager()->isMultilingual(), 'Site is mono-lingual');
+ $this->assertEqual(\Drupal::languageManager()->getDefaultLanguage()->getId(), 'fr', 'French is the default language');
+
+ // Set language detection to URL.
+ $edit = ['language_interface[enabled][language-url]' => TRUE];
+ $this->drupalPostForm('admin/config/regional/language/detection', $edit, t('Save settings'));
+ $this->drupalPlaceBlock('local_actions_block');
+ }
+
+ /**
+ * Verifies that links do not have language prefixes in them.
+ */
+ public function testPageLinks() {
+ // Navigate to 'admin/config' path.
+ $this->drupalGet('admin/config');
+
+ // Verify that links in this page do not have a 'fr/' prefix.
+ $this->assertNoLinkByHref('/fr/', 'Links do not contain language prefix');
+
+ // Verify that links in this page can be followed and work.
+ $this->clickLink(t('Languages'));
+ $this->assertResponse(200, 'Clicked link results in a valid page');
+ $this->assertText(t('Add language'), 'Page contains the add language text');
+ }
+
+}