diff --git a/core/modules/node/lib/Drupal/node/Tests/NodeTokenReplaceTest.php b/core/modules/node/lib/Drupal/node/Tests/NodeTokenReplaceTest.php
index 717abcce703..5e9e37a4b64 100644
--- a/core/modules/node/lib/Drupal/node/Tests/NodeTokenReplaceTest.php
+++ b/core/modules/node/lib/Drupal/node/Tests/NodeTokenReplaceTest.php
@@ -52,7 +52,7 @@ class NodeTokenReplaceTest extends TokenReplaceUnitTestBase {
   function testNodeTokenReplacement() {
     $url_options = array(
       'absolute' => TRUE,
-      'language' => $this->languageInterface,
+      'language' => $this->interfaceLanguage,
     );
 
     // Create a user and a node.
@@ -82,14 +82,14 @@ class NodeTokenReplaceTest extends TokenReplaceUnitTestBase {
     $tests['[node:author]'] = String::checkPlain($account->getUsername());
     $tests['[node:author:uid]'] = $node->getOwnerId();
     $tests['[node:author:name]'] = String::checkPlain($account->getUsername());
-    $tests['[node:created:since]'] = \Drupal::service('date')->formatInterval(REQUEST_TIME - $node->getCreatedTime(), 2, $this->languageInterface->id);
-    $tests['[node:changed:since]'] = \Drupal::service('date')->formatInterval(REQUEST_TIME - $node->getChangedTime(), 2, $this->languageInterface->id);
+    $tests['[node:created:since]'] = \Drupal::service('date')->formatInterval(REQUEST_TIME - $node->getCreatedTime(), 2, $this->interfaceLanguage->id);
+    $tests['[node:changed:since]'] = \Drupal::service('date')->formatInterval(REQUEST_TIME - $node->getChangedTime(), 2, $this->interfaceLanguage->id);
 
     // Test to make sure that we generated something for each token.
     $this->assertFalse(in_array(0, array_map('strlen', $tests)), 'No empty tokens generated.');
 
     foreach ($tests as $input => $expected) {
-      $output = $this->tokenService->replace($input, array('node' => $node), array('langcode' => $this->languageInterface->id));
+      $output = $this->tokenService->replace($input, array('node' => $node), array('langcode' => $this->interfaceLanguage->id));
       $this->assertEqual($output, $expected, format_string('Sanitized node token %token replaced.', array('%token' => $input)));
     }
 
@@ -101,7 +101,7 @@ class NodeTokenReplaceTest extends TokenReplaceUnitTestBase {
     $tests['[node:author:name]'] = $account->getUsername();
 
     foreach ($tests as $input => $expected) {
-      $output = $this->tokenService->replace($input, array('node' => $node), array('langcode' => $this->languageInterface->id, 'sanitize' => FALSE));
+      $output = $this->tokenService->replace($input, array('node' => $node), array('langcode' => $this->interfaceLanguage->id, 'sanitize' => FALSE));
       $this->assertEqual($output, $expected, format_string('Unsanitized node token %token replaced.', array('%token' => $input)));
     }
 
@@ -122,7 +122,7 @@ class NodeTokenReplaceTest extends TokenReplaceUnitTestBase {
     $this->assertFalse(in_array(0, array_map('strlen', $tests)), 'No empty tokens generated for node without a summary.');
 
     foreach ($tests as $input => $expected) {
-      $output = $this->tokenService->replace($input, array('node' => $node), array('language' => $this->languageInterface));
+      $output = $this->tokenService->replace($input, array('node' => $node), array('language' => $this->interfaceLanguage));
       $this->assertEqual($output, $expected, format_string('Sanitized node token %token replaced for node without a summary.', array('%token' => $input)));
     }
 
@@ -130,7 +130,7 @@ class NodeTokenReplaceTest extends TokenReplaceUnitTestBase {
     $tests['[node:summary]'] = $node->body->value;
 
     foreach ($tests as $input => $expected) {
-      $output = $this->tokenService->replace($input, array('node' => $node), array('language' => $this->languageInterface, 'sanitize' => FALSE));
+      $output = $this->tokenService->replace($input, array('node' => $node), array('language' => $this->interfaceLanguage, 'sanitize' => FALSE));
       $this->assertEqual($output, $expected, format_string('Unsanitized node token %token replaced for node without a summary.', array('%token' => $input)));
     }
   }
diff --git a/core/modules/system/lib/Drupal/system/Tests/System/TokenReplaceUnitTest.php b/core/modules/system/lib/Drupal/system/Tests/System/TokenReplaceUnitTest.php
index 623d99592e2..4ea7da1fac0 100644
--- a/core/modules/system/lib/Drupal/system/Tests/System/TokenReplaceUnitTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/System/TokenReplaceUnitTest.php
@@ -45,7 +45,7 @@ class TokenReplaceUnitTest extends TokenReplaceUnitTestBase {
     foreach ($tests as $test) {
       $input = $test['prefix'] . '[site:name]' . $test['suffix'];
       $expected = $test['prefix'] . 'Drupal' . $test['suffix'];
-      $output = $this->tokenService->replace($input, array(), array('langcode' => $this->languageInterface->id));
+      $output = $this->tokenService->replace($input, array(), array('langcode' => $this->interfaceLanguage->id));
       $this->assertTrue($output == $expected, format_string('Token recognized in string %string', array('%string' => $input)));
     }
 
@@ -66,12 +66,12 @@ class TokenReplaceUnitTest extends TokenReplaceUnitTestBase {
 
     // Replace with with the clear parameter, only the valid token should remain.
     $target = String::checkPlain(\Drupal::config('system.site')->get('name'));
-    $result = $this->tokenService->replace($source, array(), array('langcode' => $this->languageInterface->id, 'clear' => TRUE));
+    $result = $this->tokenService->replace($source, array(), array('langcode' => $this->interfaceLanguage->id, 'clear' => TRUE));
     $this->assertEqual($target, $result, 'Valid tokens replaced while invalid tokens ignored.');
 
     $target .= '[user:name]';
     $target .= '[bogus:token]';
-    $result = $this->tokenService->replace($source, array(), array('langcode' => $this->languageInterface->id));
+    $result = $this->tokenService->replace($source, array(), array('langcode' => $this->interfaceLanguage->id));
     $this->assertEqual($target, $result, 'Valid tokens replaced while invalid tokens ignored.');
   }
 
@@ -83,7 +83,7 @@ class TokenReplaceUnitTest extends TokenReplaceUnitTestBase {
     $this->installSchema('system', 'url_alias');
     $url_options = array(
       'absolute' => TRUE,
-      'language' => $this->languageInterface,
+      'language' => $this->interfaceLanguage,
     );
 
     $slogan = '<blink>Slogan</blink>';
@@ -111,7 +111,7 @@ class TokenReplaceUnitTest extends TokenReplaceUnitTestBase {
     $this->assertFalse(in_array(0, array_map('strlen', $tests)), 'No empty tokens generated.');
 
     foreach ($tests as $input => $expected) {
-      $output = $this->tokenService->replace($input, array(), array('langcode' => $this->languageInterface->id));
+      $output = $this->tokenService->replace($input, array(), array('langcode' => $this->interfaceLanguage->id));
       $this->assertEqual($output, $expected, format_string('Sanitized system site information token %token replaced.', array('%token' => $input)));
     }
 
@@ -120,7 +120,7 @@ class TokenReplaceUnitTest extends TokenReplaceUnitTestBase {
     $tests['[site:slogan]'] = $config->get('slogan');
 
     foreach ($tests as $input => $expected) {
-      $output = $this->tokenService->replace($input, array(), array('langcode' => $this->languageInterface->id, 'sanitize' => FALSE));
+      $output = $this->tokenService->replace($input, array(), array('langcode' => $this->interfaceLanguage->id, 'sanitize' => FALSE));
       $this->assertEqual($output, $expected, format_string('Unsanitized system site information token %token replaced.', array('%token' => $input)));
     }
 
@@ -146,18 +146,18 @@ class TokenReplaceUnitTest extends TokenReplaceUnitTestBase {
     // Generate and test tokens.
     $tests = array();
     $date_service = \Drupal::service('date');
-    $tests['[date:short]'] = $date_service->format($date, 'short', '', NULL, $this->languageInterface->id);
-    $tests['[date:medium]'] = $date_service->format($date, 'medium', '', NULL, $this->languageInterface->id);
-    $tests['[date:long]'] = $date_service->format($date, 'long', '', NULL, $this->languageInterface->id);
-    $tests['[date:custom:m/j/Y]'] = $date_service->format($date, 'custom', 'm/j/Y', NULL, $this->languageInterface->id);
-    $tests['[date:since]'] = $date_service->formatInterval(REQUEST_TIME - $date, 2, $this->languageInterface->id);
+    $tests['[date:short]'] = $date_service->format($date, 'short', '', NULL, $this->interfaceLanguage->id);
+    $tests['[date:medium]'] = $date_service->format($date, 'medium', '', NULL, $this->interfaceLanguage->id);
+    $tests['[date:long]'] = $date_service->format($date, 'long', '', NULL, $this->interfaceLanguage->id);
+    $tests['[date:custom:m/j/Y]'] = $date_service->format($date, 'custom', 'm/j/Y', NULL, $this->interfaceLanguage->id);
+    $tests['[date:since]'] = $date_service->formatInterval(REQUEST_TIME - $date, 2, $this->interfaceLanguage->id);
     $tests['[date:raw]'] = Xss::filter($date);
 
     // Test to make sure that we generated something for each token.
     $this->assertFalse(in_array(0, array_map('strlen', $tests)), 'No empty tokens generated.');
 
     foreach ($tests as $input => $expected) {
-      $output = $this->tokenService->replace($input, array('date' => $date), array('langcode' => $this->languageInterface->id));
+      $output = $this->tokenService->replace($input, array('date' => $date), array('langcode' => $this->interfaceLanguage->id));
       $this->assertEqual($output, $expected, format_string('Date token %token replaced.', array('%token' => $input)));
     }
   }
diff --git a/core/modules/system/lib/Drupal/system/Tests/System/TokenReplaceUnitTestBase.php b/core/modules/system/lib/Drupal/system/Tests/System/TokenReplaceUnitTestBase.php
index c13bd4c33e1..c68f2e1fc97 100644
--- a/core/modules/system/lib/Drupal/system/Tests/System/TokenReplaceUnitTestBase.php
+++ b/core/modules/system/lib/Drupal/system/Tests/System/TokenReplaceUnitTestBase.php
@@ -20,7 +20,7 @@ abstract class TokenReplaceUnitTestBase extends EntityUnitTestBase {
    *
    * @var \Drupal\Core\Language\Language
    */
-  protected $languageInterface;
+  protected $interfaceLanguage;
 
   /**
    * Token service.
@@ -41,7 +41,7 @@ abstract class TokenReplaceUnitTestBase extends EntityUnitTestBase {
     // Install default system configuration.
     $this->installConfig(array('system'));
 
-    $this->languageInterface = \Drupal::languageManager()->getCurrentLanguage();
+    $this->interfaceLanguage = \Drupal::languageManager()->getCurrentLanguage();
     $this->tokenService = \Drupal::token();
   }