diff --git a/core/core.services.yml b/core/core.services.yml
index fb62634..ba75d6d 100644
--- a/core/core.services.yml
+++ b/core/core.services.yml
@@ -147,6 +147,8 @@ services:
     factory_method: get
     factory_service: logger.factory
     arguments: ['system']
+  logger.log_message_parser:
+    class: Drupal\Core\Logger\LogMessageParser
 
   serialization.json:
     class: Drupal\Component\Serialization\Json
diff --git a/core/includes/common.inc b/core/includes/common.inc
index 8e0d53e..6e08ce0 100644
--- a/core/includes/common.inc
+++ b/core/includes/common.inc
@@ -30,6 +30,7 @@
 use Drupal\Core\Template\Attribute;
 use Drupal\Core\Render\Element;
 use Drupal\Core\Session\AnonymousUserSession;
+use Psr\Log\LogLevel;
 
 /**
  * @defgroup php_wrappers PHP wrapper functions
@@ -4099,14 +4100,14 @@ function element_set_attributes(array &$element, array $map) {
  */
 function watchdog_severity_levels() {
   return array(
-    WATCHDOG_EMERGENCY   => t('Emergency'),
-    WATCHDOG_ALERT   => t('Alert'),
-    WATCHDOG_CRITICAL    => t('Critical'),
-    WATCHDOG_ERROR     => t('Error'),
-    WATCHDOG_WARNING => t('Warning'),
-    WATCHDOG_NOTICE  => t('Notice'),
-    WATCHDOG_INFO    => t('Info'),
-    WATCHDOG_DEBUG   => t('Debug'),
+    LogLevel::EMERGENCY => t('Emergency'),
+    LogLevel::ALERT => t('Alert'),
+    LogLevel::CRITICAL => t('Critical'),
+    LogLevel::ERROR => t('Error'),
+    LogLevel::WARNING => t('Warning'),
+    LogLevel::NOTICE => t('Notice'),
+    LogLevel::INFO => t('Info'),
+    LogLevel::DEBUG => t('Debug'),
   );
 }
 
diff --git a/core/lib/Drupal/Core/Logger/LogMessageParser.php b/core/lib/Drupal/Core/Logger/LogMessageParser.php
new file mode 100644
index 0000000..ba99129
--- /dev/null
+++ b/core/lib/Drupal/Core/Logger/LogMessageParser.php
@@ -0,0 +1,46 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\Logger\LogMessageParser.
+ */
+
+namespace Drupal\Core\Logger;
+
+/**
+ * Parses log messages and their placeholders.
+ */
+class LogMessageParser implements LogMessageParserInterface {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function parseMessagePlaceholders(&$message, array &$context) {
+    $variables = array();
+    $has_psr3 = FALSE;
+    if (($start = strpos($message, '{')) !== FALSE && strpos($message, '}') > $start) {
+      $has_psr3 = TRUE;
+      // Transform PSR3 style messages containing placeholders to
+      // \Drupal\Component\Utility\String::format() style.
+      $message = preg_replace('/\{(.*)\}/U', '@$1', $message);
+    }
+    foreach ($context as $key => $variable) {
+      // PSR3 style placeholders.
+      if ($has_psr3) {
+        // Keys are not prefixed with anything according to PSR3 specs.
+        // If the message is "User {username} created" the variable key will be
+        // just "username".
+        if (strpos($message, '@' . $key) !== FALSE) {
+          $key = '@' . $key;
+        }
+      }
+      if (!empty($key) && ($key[0] === '@' || $key[0] === '%' || $key[0] === '!')) {
+        // The key is now in \Drupal\Component\Utility\String::format() style.
+        $variables[$key] = $variable;
+      }
+    }
+
+    return $variables;
+  }
+
+}
diff --git a/core/lib/Drupal/Core/Logger/LogMessageParserInterface.php b/core/lib/Drupal/Core/Logger/LogMessageParserInterface.php
new file mode 100644
index 0000000..545b039
--- /dev/null
+++ b/core/lib/Drupal/Core/Logger/LogMessageParserInterface.php
@@ -0,0 +1,39 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\Logger\LogMessageParserInterface.
+ */
+
+namespace Drupal\Core\Logger;
+
+/**
+ * Defines an interface for parsing log messages and their placeholders.
+ */
+interface LogMessageParserInterface {
+
+  /**
+   * Parses and transforms message and its placeholders to a common format.
+   *
+   * For a value to be considered as a placeholder should be in the following
+   * formats:
+   *   - PSR3 format:
+   *     @see https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-3-logger-interface.md#12-message
+   *   - Drupal specific string placeholder format:
+   *     @see \Drupal\Component\Utility\String::format()
+   *
+   * Values in PSR3 format will be transformed to String::format() format.
+   *
+   * @param string $message
+   *   The message that contains the placeholders.
+   *   If the message is in PSR3 style, it will be transformed to
+   *   \Drupal\Component\Utility\String::format() style.
+   * @param array $context
+   *   An array that may or may not contain placeholder variables.
+   *
+   * @return array
+   *   An array of the extracted message placeholders.
+   */
+  public function parseMessagePlaceholders(&$message, array &$context);
+
+}
diff --git a/core/lib/Drupal/Core/Logger/LogMessageParserTrait.php b/core/lib/Drupal/Core/Logger/LogMessageParserTrait.php
deleted file mode 100644
index 309f1e1..0000000
--- a/core/lib/Drupal/Core/Logger/LogMessageParserTrait.php
+++ /dev/null
@@ -1,62 +0,0 @@
-<?php
-
-/**
- * @file
- * Contains \Drupal\Core\Logger\LogMessageParserTrait.
- */
-
-namespace Drupal\Core\Logger;
-
-/**
- * Defines a trait for parsing log messages and their placeholders.
- */
-trait LogMessageParserTrait {
-
-  /**
-   * Parses and transforms message and its placeholders to a common format.
-   *
-   * For a value to be considered as a placeholder should be in the following
-   * formats:
-   *   - PSR3 format:
-   *     @see https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-3-logger-interface.md#12-message
-   *   - Drupal specific string placeholder format:
-   *     @see \Drupal\Component\Utility\String::format()
-   *
-   * Values in PSR3 format will be transformed to String::format() format.
-   *
-   * @param string $message
-   *   The message that contains the placeholders.
-   *   If the message is in PSR3 style, it will be transformed to
-   *   \Drupal\Component\Utility\String::format() style.
-   * @param array $context
-   *   An array that may or may not contain placeholder variables.
-   *   $context['variables'] will contain the transformed variables.
-   */
-  protected function parseMessagePlaceholders(&$message, array &$context) {
-    $variables = array();
-    $has_psr3 = FALSE;
-    if (($start = strpos($message, '{')) !== FALSE && strpos($message, '}') > $start) {
-      $has_psr3 = TRUE;
-      // Transform PSR3 style messages containing placeholders to
-      // \Drupal\Component\Utility\String::format() style.
-      $message = preg_replace('/\{(.*)\}/U', '@$1', $message);
-    }
-    foreach ($context as $key => $variable) {
-      // PSR3 style placeholders.
-      if ($has_psr3) {
-        // Keys are not prefixed with anything according to PSR3 specs.
-        // If the message is "User {username} created" the variable key will be
-        // just "username".
-        if (strpos($message, '@' . $key) !== FALSE) {
-          $key = '@' . $key;
-        }
-      }
-      if (!empty($key) && ($key[0] === '@' || $key[0] === '%' || $key[0] === '!')) {
-        // The key is now in \Drupal\Component\Utility\String::format() style.
-        $variables[$key] = $variable;
-      }
-    }
-    $context['variables'] = $variables;
-  }
-
-}
diff --git a/core/lib/Drupal/Core/Logger/LoggerChannel.php b/core/lib/Drupal/Core/Logger/LoggerChannel.php
index 3cc64e7..86bf2cf 100644
--- a/core/lib/Drupal/Core/Logger/LoggerChannel.php
+++ b/core/lib/Drupal/Core/Logger/LoggerChannel.php
@@ -21,6 +21,8 @@ class LoggerChannel implements LoggerChannelInterface {
 
   /**
    * The name of the channel of this logger instance.
+   *
+   * @var string
    */
   protected $channel;
 
@@ -33,14 +35,14 @@ class LoggerChannel implements LoggerChannelInterface {
    * @var array
    */
   protected $levelTranslation = array(
-    LogLevel::EMERGENCY => WATCHDOG_EMERGENCY,
-    LogLevel::ALERT => WATCHDOG_ALERT,
-    LogLevel::CRITICAL => WATCHDOG_CRITICAL,
-    LogLevel::ERROR => WATCHDOG_ERROR,
-    LogLevel::WARNING => WATCHDOG_WARNING,
-    LogLevel::NOTICE => WATCHDOG_NOTICE,
-    LogLevel::INFO => WATCHDOG_INFO,
-    LogLevel::DEBUG => WATCHDOG_DEBUG,
+    WATCHDOG_EMERGENCY => LogLevel::EMERGENCY,
+    WATCHDOG_ALERT => LogLevel::ALERT,
+    WATCHDOG_CRITICAL => LogLevel::CRITICAL,
+    WATCHDOG_ERROR => LogLevel::ERROR,
+    WATCHDOG_WARNING => LogLevel::WARNING,
+    WATCHDOG_NOTICE => LogLevel::NOTICE,
+    WATCHDOG_INFO => LogLevel::INFO,
+    WATCHDOG_DEBUG => LogLevel::DEBUG,
   );
 
   /**
@@ -100,8 +102,10 @@ public function log($level, $message, array $context = array()) {
       $context['ip'] = $this->request->getClientIP();
     }
 
-    if (is_string($level)) {
-      // Convert to integer equivalent for BC.
+    if (!is_string($level)) {
+      // Convert integer levels (WATCHDOG_* constants) to the string equivalents
+      // of \Psr\Log\LogLevel.
+      // @todo Remove this when watchdog() is removed.
       $level = $this->levelTranslation[$level];
     }
     // Call all available loggers.
diff --git a/core/modules/dblog/dblog.install b/core/modules/dblog/dblog.install
index b7454c1..a6ceaf0 100644
--- a/core/modules/dblog/dblog.install
+++ b/core/modules/dblog/dblog.install
@@ -44,12 +44,11 @@ function dblog_schema() {
         'description' => 'Serialized array of variables that match the message string and that is passed into the t() function.',
       ),
       'severity' => array(
-        'type' => 'int',
-        'unsigned' => TRUE,
+        'type' => 'varchar',
+        'length' => 64,
         'not null' => TRUE,
-        'default' => 0,
-        'size' => 'tiny',
-        'description' => 'The severity level of the event; ranges from 0 (Emergency) to 7 (Debug)',
+        'default' => '',
+        'description' => 'The severity level of the event. See \Psr\Log\LogLevel',
       ),
       'link' => array(
         'type' => 'varchar',
diff --git a/core/modules/dblog/dblog.services.yml b/core/modules/dblog/dblog.services.yml
index c07cb32..38836e1 100644
--- a/core/modules/dblog/dblog.services.yml
+++ b/core/modules/dblog/dblog.services.yml
@@ -1,6 +1,6 @@
 services:
   logger.dblog:
     class: Drupal\dblog\Logger\DbLog
-    arguments: ['@database']
+    arguments: ['@database', '@logger.log_message_parser']
     tags:
       - { name: logger }
diff --git a/core/modules/dblog/lib/Drupal/dblog/Controller/DbLogController.php b/core/modules/dblog/lib/Drupal/dblog/Controller/DbLogController.php
index 72ddf22..08123b3 100644
--- a/core/modules/dblog/lib/Drupal/dblog/Controller/DbLogController.php
+++ b/core/modules/dblog/lib/Drupal/dblog/Controller/DbLogController.php
@@ -15,6 +15,7 @@
 use Drupal\Core\Datetime\Date;
 use Drupal\Core\Extension\ModuleHandlerInterface;
 use Drupal\Core\Form\FormBuilderInterface;
+use Psr\Log\LogLevel;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 
 /**
@@ -89,14 +90,14 @@ public function __construct(Connection $database, ModuleHandlerInterface $module
    */
   public static function getLogLevelClassMap() {
     return array(
-      WATCHDOG_DEBUG => 'dblog-debug',
-      WATCHDOG_INFO => 'dblog-info',
-      WATCHDOG_NOTICE => 'dblog-notice',
-      WATCHDOG_WARNING => 'dblog-warning',
-      WATCHDOG_ERROR => 'dblog-error',
-      WATCHDOG_CRITICAL => 'dblog-critical',
-      WATCHDOG_ALERT => 'dblog-alert',
-      WATCHDOG_EMERGENCY => 'dblog-emergency',
+      LogLevel::DEBUG => 'dblog-debug',
+      LogLevel::INFO => 'dblog-info',
+      LogLevel::NOTICE => 'dblog-notice',
+      LogLevel::WARNING => 'dblog-warning',
+      LogLevel::ERROR => 'dblog-error',
+      LogLevel::CRITICAL => 'dblog-critical',
+      LogLevel::ALERT => 'dblog-alert',
+      LogLevel::EMERGENCY => 'dblog-emergency',
     );
   }
 
diff --git a/core/modules/dblog/lib/Drupal/dblog/Logger/DbLog.php b/core/modules/dblog/lib/Drupal/dblog/Logger/DbLog.php
index 80d7136..14916b3 100644
--- a/core/modules/dblog/lib/Drupal/dblog/Logger/DbLog.php
+++ b/core/modules/dblog/lib/Drupal/dblog/Logger/DbLog.php
@@ -8,7 +8,7 @@
 namespace Drupal\dblog\Logger;
 
 use Drupal\Core\Database\Connection;
-use Drupal\Core\Logger\LogMessageParserTrait;
+use Drupal\Core\Logger\LogMessageParserInterface;
 use Psr\Log\LoggerInterface;
 use Psr\Log\LoggerTrait;
 
@@ -17,7 +17,6 @@
  */
 class DbLog implements LoggerInterface {
   use LoggerTrait;
-  use LogMessageParserTrait;
 
   /**
    * The database connection object.
@@ -27,13 +26,23 @@ class DbLog implements LoggerInterface {
   protected $database;
 
   /**
+   * The message's placeholders parser.
+   *
+   * @var \Drupal\Core\Logger\LogMessageParserInterface
+   */
+  protected $parser;
+
+  /**
    * Constructs a DbLog object.
    *
    * @param \Drupal\Core\Database\Connection $database
    *   The database connection object.
+   * @param \Drupal\Core\Logger\LogMessageParserInterface $parser
+   *   The parser to use when extracting message variables.
    */
-  public function __construct(Connection $database) {
+  public function __construct(Connection $database, LogMessageParserInterface $parser) {
     $this->database = $database;
+    $this->parser = $parser;
   }
 
   /**
@@ -45,7 +54,7 @@ public function log($level, $message, array $context = array()) {
 
     // Convert PSR3-style messages to String::format() style, so they can be
     // translated too in runtime.
-    $this->parseMessagePlaceholders($message, $context);
+    $message_placeholders = $this->parser->parseMessagePlaceholders($message, $context);
 
     $this->database
       ->insert('watchdog')
@@ -53,7 +62,7 @@ public function log($level, $message, array $context = array()) {
         'uid' => $context['uid'],
         'type' => substr($context['channel'], 0, 64),
         'message' => $message,
-        'variables' => serialize($context['variables']),
+        'variables' => serialize($message_placeholders),
         'severity' => $level,
         'link' => substr($context['link'], 0, 255),
         'location' => $context['request_uri'],
diff --git a/core/modules/dblog/lib/Drupal/dblog/Tests/DbLogTest.php b/core/modules/dblog/lib/Drupal/dblog/Tests/DbLogTest.php
index 2ac6c53..a16625b 100644
--- a/core/modules/dblog/lib/Drupal/dblog/Tests/DbLogTest.php
+++ b/core/modules/dblog/lib/Drupal/dblog/Tests/DbLogTest.php
@@ -11,6 +11,7 @@
 use Drupal\Core\Language\Language;
 use Drupal\dblog\Controller\DbLogController;
 use Drupal\simpletest\WebTestBase;
+use Psr\Log\LogLevel;
 
 /**
  * Tests logging messages to the database.
@@ -123,9 +124,10 @@ private function verifyCron($row_limit) {
    * @param string $type
    *   (optional) The type of watchdog entry. Defaults to 'custom'.
    * @param int $severity
-   *   (optional) The severity of the watchdog entry. Defaults to WATCHDOG_NOTICE.
+   *   (optional) The severity of the watchdog entry.
+   *   Defaults to \Psr\Log\LogLevel::NOTICE.
    */
-  private function generateLogEntries($count, $type = 'custom', $severity = WATCHDOG_NOTICE) {
+  private function generateLogEntries($count, $type = 'custom', $severity = LogLevel::NOTICE) {
     global $base_root;
 
     // Prepare the fields to be logged
@@ -416,7 +418,7 @@ protected function testDBLogAddAndClear() {
       'channel'     => 'system',
       'message'     => 'Log entry added to test the doClearTest clear down.',
       'variables'   => array(),
-      'severity'    => WATCHDOG_NOTICE,
+      'severity'    => LogLevel::NOTICE,
       'link'        => NULL,
       'user'        => $this->big_user,
       'uid'         => $this->big_user->id(),
@@ -452,12 +454,15 @@ protected function testFilter() {
     $types = array();
     for ($i = 0; $i < 3; $i++) {
       $type_names[] = $type_name = $this->randomName();
-      $severity = WATCHDOG_EMERGENCY;
       for ($j = 0; $j < 3; $j++) {
+        $severity = LogLevel::EMERGENCY;
+        if ($j) {
+          $severity = $j === 1 ? LogLevel::ALERT : LogLevel::CRITICAL;
+        }
         $types[] = $type = array(
           'count' => $j + 1,
           'type' => $type_name,
-          'severity' => $severity++,
+          'severity' => $severity,
         );
         $this->generateLogEntries($type['count'], $type['type'], $type['severity']);
       }
@@ -531,7 +536,7 @@ protected function getLogEntries() {
       foreach ($table->tbody->tr as $row) {
         $entries[] = array(
           'severity' => $this->getSeverityConstant($row['class']),
-          'channel' => $this->asText($row->td[1]),
+          'type' => $this->asText($row->td[1]),
           'message' => $this->asText($row->td[3]),
           'user' => $this->asText($row->td[4]),
         );
@@ -554,7 +559,7 @@ protected function getTypeCount(array $types) {
     $count = array_fill(0, count($types), 0);
     foreach ($entries as $entry) {
       foreach ($types as $key => $type) {
-        if ($entry['channel'] == $type['type'] && $entry['severity'] == $type['severity']) {
+        if ($entry['type'] == $type['type'] && $entry['severity'] == $type['severity']) {
           $count[$key]++;
           break;
         }
diff --git a/core/modules/syslog/lib/Drupal/syslog/Logger/SysLog.php b/core/modules/syslog/lib/Drupal/syslog/Logger/SysLog.php
index 17dd040..7b3ecd0 100644
--- a/core/modules/syslog/lib/Drupal/syslog/Logger/SysLog.php
+++ b/core/modules/syslog/lib/Drupal/syslog/Logger/SysLog.php
@@ -8,16 +8,16 @@
 namespace Drupal\syslog\Logger;
 
 use Drupal\Core\Config\ConfigFactory;
-use Drupal\Core\Logger\LogMessageParserTrait;
+use Drupal\Core\Logger\LogMessageParserInterface;
 use Psr\Log\LoggerInterface;
 use Psr\Log\LoggerTrait;
+use Psr\Log\LogLevel;
 
 /**
  * Redirects logging messages to syslog.
  */
 class SysLog implements LoggerInterface {
   use LoggerTrait;
-  use LogMessageParserTrait;
 
   /**
    * A configuration object containin syslog settings.
@@ -27,6 +27,13 @@ class SysLog implements LoggerInterface {
   protected $config;
 
   /**
+   * The message's placeholders parser.
+   *
+   * @var \Drupal\Core\Logger\LogMessageParserInterface
+   */
+  protected $parser;
+
+  /**
    * Stores whether there is a system logger connection opened or not.
    *
    * @var bool
@@ -34,13 +41,35 @@ class SysLog implements LoggerInterface {
   protected $connectionOpened = FALSE;
 
   /**
+   * Map of PSR Log constants to Watchdog log constants.
+   *
+   * @todo Move watchdog constants to syslog's module namespace, after
+   * watchdog() is removed.
+   *
+   * @var array
+   */
+  protected $levelTranslation = array(
+    LogLevel::EMERGENCY => WATCHDOG_EMERGENCY,
+    LogLevel::ALERT => WATCHDOG_ALERT,
+    LogLevel::CRITICAL => WATCHDOG_CRITICAL,
+    LogLevel::ERROR => WATCHDOG_ERROR,
+    LogLevel::WARNING => WATCHDOG_WARNING,
+    LogLevel::NOTICE => WATCHDOG_NOTICE,
+    LogLevel::INFO => WATCHDOG_INFO,
+    LogLevel::DEBUG => WATCHDOG_DEBUG,
+  );
+
+  /**
    * Constructs a SysLog object.
    *
    * @param \Drupal\Core\Config\ConfigFactory $config_factory
    *   The configuration factory object.
+   * @param \Drupal\Core\Logger\LogMessageParserInterface $parser
+   *   The parser to use when extracting message variables.
    */
-  public function __construct(ConfigFactory $config_factory) {
+  public function __construct(ConfigFactory $config_factory, LogMessageParserInterface $parser) {
     $this->config = $config_factory->get('syslog.settings');
+    $this->parser = $parser;
   }
 
   /**
@@ -65,8 +94,9 @@ public function log($level, $message, array $context = array()) {
     // Ensure we have a connection available.
     $this->openConnection();
 
-    // Populate the $context['variables'] with the message placeholders.
-    $this->parseMessagePlaceholders($message, $context);
+    // Populate the message placeholders and then replace them in the message.
+    $message_placeholders = $this->parser->parseMessagePlaceholders($message, $context);
+    $message = empty($message_placeholders) ? $message : strtr($message, $message_placeholders);
 
     $entry = strtr($this->config->get('format'), array(
       '!base_url' => $base_url,
@@ -77,10 +107,10 @@ public function log($level, $message, array $context = array()) {
       '!referer' => $context['referer'],
       '!uid' => $context['uid'],
       '!link' => strip_tags($context['link']),
-      '!message' => strip_tags(empty($context['variables']) ? $message : strtr($message, $context['variables'])),
+      '!message' => strip_tags($message),
     ));
 
-    syslog($level, $entry);
+    syslog($this->levelTranslation[$level], $entry);
   }
 
 }
diff --git a/core/modules/syslog/syslog.services.yml b/core/modules/syslog/syslog.services.yml
index 98f6041..78c7d38 100644
--- a/core/modules/syslog/syslog.services.yml
+++ b/core/modules/syslog/syslog.services.yml
@@ -1,6 +1,6 @@
 services:
   logger.syslog:
     class: Drupal\syslog\Logger\SysLog
-    arguments: ['@config.factory']
+    arguments: ['@config.factory', '@logger.log_message_parser']
     tags:
       - { name: logger }
diff --git a/core/tests/Drupal/Tests/Core/Logger/LogMessageParserTraitTest.php b/core/tests/Drupal/Tests/Core/Logger/LogMessageParserTest.php
similarity index 79%
rename from core/tests/Drupal/Tests/Core/Logger/LogMessageParserTraitTest.php
rename to core/tests/Drupal/Tests/Core/Logger/LogMessageParserTest.php
index a7b81cf..e30f551 100644
--- a/core/tests/Drupal/Tests/Core/Logger/LogMessageParserTraitTest.php
+++ b/core/tests/Drupal/Tests/Core/Logger/LogMessageParserTest.php
@@ -7,23 +7,24 @@
 
 namespace Drupal\Tests\Core\Logger;
 
+use Drupal\Core\Logger\LogMessageParser;
 use Drupal\Tests\UnitTestCase;
 
 /**
- * Tests the log message parser trait.
+ * Tests the log message parser.
  *
- * @see \Drupal\Core\Logger\LogMessageParserTrait
- * @coversDefaultClass \Drupal\Core\Logger\LogMessageParserTrait
+ * @see \Drupal\Core\Logger\LogMessageParser
+ * @coversDefaultClass \Drupal\Core\Logger\LogMessageParser
  *
  * @group Drupal
  * @group Logger
  */
-class LogMessageParserTraitTest extends UnitTestCase {
+class LogMessageParserTest extends UnitTestCase {
 
   public static function getInfo() {
     return array(
       'name' => 'Log message parser',
-      'description' => 'Unit tests for the log message parser trait.',
+      'description' => 'Unit tests for the log message parser.',
       'group' => 'Logger',
     );
   }
@@ -32,7 +33,7 @@ public static function getInfo() {
    * {@inheritdoc}
    */
   protected function setUp() {
-    $this->logger = $this->getObjectForTrait('Drupal\Core\Logger\LogMessageParserTrait');
+    $this->parser = new LogMessageParser();
   }
 
   /**
@@ -51,12 +52,9 @@ protected function setUp() {
    * @covers ::parseMessagePlaceholders
    */
   public function testParseMessagePlaceholders(array $value, array $expected) {
-    $class = new \ReflectionClass($this->logger);
-    $method = $class->getMethod('parseMessagePlaceholders');
-    $method->setAccessible(TRUE);
-    $method->invokeArgs($this->logger, array(&$value['message'], &$value['context']));
+    $message_placeholders = $this->parser->parseMessagePlaceholders($value['message'], $value['context']);
     $this->assertEquals($expected['message'], $value['message']);
-    $this->assertEquals($expected['context'], $value['context']['variables']);
+    $this->assertEquals($expected['context'], $message_placeholders);
   }
 
   /**
diff --git a/core/tests/Drupal/Tests/Core/Logger/LoggerChannelFactoryTest.php b/core/tests/Drupal/Tests/Core/Logger/LoggerChannelFactoryTest.php
index 9c29831..82e20b2 100644
--- a/core/tests/Drupal/Tests/Core/Logger/LoggerChannelFactoryTest.php
+++ b/core/tests/Drupal/Tests/Core/Logger/LoggerChannelFactoryTest.php
@@ -18,10 +18,13 @@
   define('WATCHDOG_ALERT', 1);
   define('WATCHDOG_CRITICAL', 2);
   define('WATCHDOG_WARNING', 4);
-  define('WATCHDOG_NOTICE', 5);
   define('WATCHDOG_INFO', 6);
   define('WATCHDOG_DEBUG', 7);
 }
+// WATCHDOG_NOTICE is also defined in FormValidatorTest, so check independently.
+if (!defined('WATCHDOG_NOTICE')) {
+  define('WATCHDOG_NOTICE', 5);
+}
 // WATCHDOG_ERROR is also defined in FormBuilderTest, so check independently.
 if (!defined('WATCHDOG_ERROR')) {
   define('WATCHDOG_ERROR', 3);
diff --git a/core/tests/Drupal/Tests/Core/Logger/LoggerChannelTest.php b/core/tests/Drupal/Tests/Core/Logger/LoggerChannelTest.php
index c62cf41..2cc0a50 100644
--- a/core/tests/Drupal/Tests/Core/Logger/LoggerChannelTest.php
+++ b/core/tests/Drupal/Tests/Core/Logger/LoggerChannelTest.php
@@ -18,10 +18,13 @@
   define('WATCHDOG_ALERT', 1);
   define('WATCHDOG_CRITICAL', 2);
   define('WATCHDOG_WARNING', 4);
-  define('WATCHDOG_NOTICE', 5);
   define('WATCHDOG_INFO', 6);
   define('WATCHDOG_DEBUG', 7);
 }
+// WATCHDOG_NOTICE is also defined in FormValidatorTest, so check independently.
+if (!defined('WATCHDOG_NOTICE')) {
+  define('WATCHDOG_NOTICE', 5);
+}
 // WATCHDOG_ERROR is also defined in FormBuilderTest, so check independently.
 if (!defined('WATCHDOG_ERROR')) {
   define('WATCHDOG_ERROR', 3);