diff --git a/core/lib/Drupal/Core/Messenger/LegacyMessenger.php b/core/lib/Drupal/Core/Messenger/LegacyMessenger.php
index ff323d20f94..35e3609a52e 100644
--- a/core/lib/Drupal/Core/Messenger/LegacyMessenger.php
+++ b/core/lib/Drupal/Core/Messenger/LegacyMessenger.php
@@ -180,7 +180,7 @@ class LegacyMessenger implements MessengerInterface {
   public function deleteByType($type) {
     // Proxy to the Messenger service, if it exists.
     if ($messenger = $this->getMessengerService()) {
-      return $messenger->messagesByType($type);
+      return $messenger->deleteByType($type);
     }
 
     $messages = static::$messages[$type];
diff --git a/core/modules/file/tests/src/Functional/SaveUploadFormTest.php b/core/modules/file/tests/src/Functional/SaveUploadFormTest.php
index 6167e268bef..e8b14e6ba12 100644
--- a/core/modules/file/tests/src/Functional/SaveUploadFormTest.php
+++ b/core/modules/file/tests/src/Functional/SaveUploadFormTest.php
@@ -424,7 +424,7 @@ class SaveUploadFormTest extends FileManagedTestBase {
     // after calling _file_save_upload_from_form() are correct.
     $this->assertText($error);
     $this->assertRaw('Number of error messages before _file_save_upload_from_form(): 1');
-    $this->assertRaw('Number of error messages after _file_save_upload_from_form(): 2');
+    $this->assertRaw('Number of error messages after _file_save_upload_from_form(): 1');
 
     // Test a successful upload with no messages.
     $edit = [
diff --git a/core/tests/Drupal/KernelTests/Core/Messenger/MessengerLegacyTest.php b/core/tests/Drupal/KernelTests/Core/Messenger/MessengerLegacyTest.php
index 29334647db1..be687f8c593 100644
--- a/core/tests/Drupal/KernelTests/Core/Messenger/MessengerLegacyTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Messenger/MessengerLegacyTest.php
@@ -103,6 +103,11 @@ class MessengerLegacyTest extends KernelTestBase {
     $this->assertCount(4, $messages[MessengerInterface::TYPE_STATUS]);
     $this->assertCount(4, $messages[MessengerInterface::TYPE_WARNING]);
     $this->assertCount(4, $messages[MessengerInterface::TYPE_ERROR]);
+
+    // Test deleteByType().
+    $this->assertCount(4, $messenger->deleteByType(MessengerInterface::TYPE_WARNING));
+    $this->assertCount(0, $messenger->messagesByType(MessengerInterface::TYPE_WARNING));
+    $this->assertCount(4, $messenger->messagesByType(MessengerInterface::TYPE_ERROR));
   }
 
 }