diff --git a/devel.module b/devel.module
index 6364d2b..d4a1132 100644
--- a/devel.module
+++ b/devel.module
@@ -20,6 +20,7 @@ use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Logger\RfcLogLevel;
 use Drupal\Core\Menu\LocalTaskDefault;
+use Drupal\Core\Messenger\MessengerInterface;
 use Drupal\Core\Render\Element;
 use Drupal\Core\Routing\RouteMatchInterface;
 use Drupal\Core\Url;
@@ -148,7 +149,7 @@ function devel_set_message($msg, $type = NULL) {
     drush_log($msg, $type);
   }
   else {
-    drupal_set_message($msg, $type, TRUE);
+    \Drupal::messenger()->addMessage($msg, $type, TRUE);
   }
 }
 
@@ -262,7 +263,7 @@ function backtrace_error_handler($error_level, $message, $filename, $line, $cont
     if (\Drupal::config('system.logging')->get('error_level') != 'hide') {
       $error_handlers = devel_get_handlers();
       if (!empty($error_handlers[DEVEL_ERROR_HANDLER_STANDARD])) {
-        drupal_set_message($msg, ($severity_level <= RfcLogLevel::NOTICE ? 'error' : 'warning'), TRUE);
+        \Drupal::messenger()->addMessage($msg, ($severity_level <= RfcLogLevel::NOTICE ? MessengerInterface::TYPE_ERROR : MessengerInterface::TYPE_WARNING), TRUE);
       }
       if (!empty($error_handlers[DEVEL_ERROR_HANDLER_BACKTRACE_KINT])) {
         print kpr(ddebug_backtrace(TRUE, 1), TRUE, $msg);
@@ -350,21 +351,21 @@ if (!function_exists('ddm')) {
  *
  * Prints a variable to the 'message' area of the page.
  *
- * Uses drupal_set_message().
+ * Uses Drupal\Core\Messenger\MessengerInterface::addMessage()
  *
  * @param $input
  *   An arbitrary value to output.
  * @param string $name
  *   Optional name for identifying the output.
  * @param string $type
- *   Optional message type for drupal_set_message(), defaults to 'status'.
+ *   Optional message type see MessengerInterface, defaults to TYPE_STATUS.
  *
  * @return input
  *   The unaltered input value.
  *
  * @see \Drupal\devel\DevelDumperManager::message()
  */
-function dpm($input, $name = NULL, $type = 'status') {
+function dpm($input, $name = NULL, $type = MessengerInterface::TYPE_STATUS) {
   \Drupal::service('devel.dumper')->message($input, $name, $type);
   return $input;
 }
@@ -374,7 +375,7 @@ function dpm($input, $name = NULL, $type = 'status') {
  *
  * Displays a Variable::export() variable to the 'message' area of the page.
  *
- * Uses drupal_set_message().
+ * Uses Drupal\Core\Messenger\MessengerInterface::addMessage()
  *
  * @param $input
  *   An arbitrary value to output.
@@ -387,7 +388,7 @@ function dpm($input, $name = NULL, $type = 'status') {
  * @see \Drupal\devel\DevelDumperManager::message()
  */
 function dvm($input, $name = NULL) {
-  \Drupal::service('devel.dumper')->message($input, $name, 'status', 'drupal_variable');
+  \Drupal::service('devel.dumper')->message($input, $name, MessengerInterface::TYPE_STATUS, 'drupal_variable');
   return $input;
 }
 
diff --git a/devel_generate/devel_generate.batch.inc b/devel_generate/devel_generate.batch.inc
index 2bfa690..3ec35c7 100644
--- a/devel_generate/devel_generate.batch.inc
+++ b/devel_generate/devel_generate.batch.inc
@@ -21,5 +21,5 @@ function devel_generate_batch_finished($success, $results, $operations) {
   else {
     $message = t('Finished with an error.');
   }
-  drupal_set_message($message);
+  \Drupal::messenger()->addMessage($message);
 }
diff --git a/devel_generate/src/DevelGenerateBase.php b/devel_generate/src/DevelGenerateBase.php
index 1d38a35..18ffe33 100644
--- a/devel_generate/src/DevelGenerateBase.php
+++ b/devel_generate/src/DevelGenerateBase.php
@@ -6,6 +6,7 @@ use Drupal\Component\Utility\Random;
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Field\FieldStorageDefinitionInterface;
 use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Messenger\MessengerInterface;
 use Drupal\Core\Plugin\PluginBase;
 
 /**
@@ -126,16 +127,17 @@ abstract class DevelGenerateBase extends PluginBase implements DevelGenerateBase
    * @param string $msg
    *   The message to display.
    * @param string $type
-   *   (optional) The message type, as defined by drupal_set_message(). Defaults
-   *   to 'status'
+   *   (optional) The message type, as defined in MessengerInterface. Defaults
+   *   to MessengerInterface::TYPE_STATUS
    */
-  protected function setMessage($msg, $type = 'status') {
-    $function = 'drupal_set_message';
+  protected function setMessage($msg, $type = MessengerInterface::TYPE_STATUS) {
     if (function_exists('drush_log')) {
-      $function = 'drush_log';
       $msg = strip_tags($msg);
+      drush_log($msg);
+    }
+    else {
+      \Drupal::messenger()->addMessage($msg, $type);
     }
-    $function($msg, $type);
   }
 
   /**
diff --git a/devel_generate/src/Form/DevelGenerateForm.php b/devel_generate/src/Form/DevelGenerateForm.php
index 72366b8..bc9b7d6 100644
--- a/devel_generate/src/Form/DevelGenerateForm.php
+++ b/devel_generate/src/Form/DevelGenerateForm.php
@@ -107,7 +107,7 @@ class DevelGenerateForm extends FormBase {
     }
     catch (DevelGenerateException $e) {
       $this->logger('DevelGenerate', $this->t('Failed to generate elements due to "%error".', array('%error' => $e->getMessage())));
-      drupal_set_message($this->t('Failed to generate elements due to "%error".', array('%error' => $e->getMessage())));
+      $this->messenger()->addMessage($this->t('Failed to generate elements due to "%error".', array('%error' => $e->getMessage())));
     }
   }
 
diff --git a/kint/kint.module b/kint/kint.module
index c8bef22..53d7c5d 100644
--- a/kint/kint.module
+++ b/kint/kint.module
@@ -53,7 +53,7 @@ function ksm() {
   if (\Drupal::currentUser()->hasPermission('access kint')) {
     $args = func_get_args();
     $msg = @Kint::dump($args);
-    drupal_set_message(Markup::create($msg));
+    \Drupal::messenger()->addMessage(Markup::create($msg));
   }
 }
 
diff --git a/src/DevelDumperManager.php b/src/DevelDumperManager.php
index 95c2f56..be60c02 100644
--- a/src/DevelDumperManager.php
+++ b/src/DevelDumperManager.php
@@ -90,10 +90,10 @@ class DevelDumperManager implements DevelDumperManagerInterface {
   /**
    * {@inheritdoc}
    */
-  public function message($input, $name = NULL, $type = 'status', $plugin_id = NULL) {
+  public function message($input, $name = NULL, $type = MessengerInterface::TYPE_STATUS, $plugin_id = NULL) {
     if ($this->hasAccessToDevelInformation()) {
       $output = $this->export($input, $name, $plugin_id);
-      $this->messenger()->addStatus($output);
+      $this->messenger->addMessage($output, $type, TRUE);
     }
   }
 
diff --git a/src/Form/SystemStateEdit.php b/src/Form/SystemStateEdit.php
index e48016e..e08345c 100644
--- a/src/Form/SystemStateEdit.php
+++ b/src/Form/SystemStateEdit.php
@@ -155,7 +155,6 @@ class SystemStateEdit extends FormBase {
     $this->state->set($values['state_name'], $values['parsed_value']);
 
     $form_state->setRedirectUrl(Url::fromRoute('devel.state_system_page'));
-    
     $this->messenger()->addMessage($this->t('Variable %variable was successfully edited.', array('%variable' => $values['state_name'])));
     $this->logger('devel')->info('Variable %variable was successfully edited.', array('%variable' => $values['state_name']));
   }
diff --git a/webprofiler/src/Form/ConfigForm.php b/webprofiler/src/Form/ConfigForm.php
index d95582b..2d77bc0 100644
--- a/webprofiler/src/Form/ConfigForm.php
+++ b/webprofiler/src/Form/ConfigForm.php
@@ -207,7 +207,7 @@ class ConfigForm extends ConfigFormBase {
    */
   public function purge(array &$form, FormStateInterface $form_state) {
     $this->profiler->purge();
-    drupal_set_message($this->t('Profiles purged'));
+    $this->messenger()->addMessage($this->t('Profiles purged'));
   }
 
   /**