diff -u b/core/modules/media/tests/src/Kernel/MediaSourceTest.php b/core/modules/media/tests/src/Kernel/MediaSourceTest.php
--- b/core/modules/media/tests/src/Kernel/MediaSourceTest.php
+++ b/core/modules/media/tests/src/Kernel/MediaSourceTest.php
@@ -434,26 +434,26 @@
     /** @var \Drupal\media\MediaSourceInterface $source */
     $source = $manager->createInstance('test', []);
     $source->submitConfigurationForm($form, $form_state);
-    $expected = ['test_config_value' => 'Somewhere over the rainbow.', 'source_field' => 'field_media_test_1'];
-    $this->assertEquals($expected, $source->getConfiguration(), 'Submitted values were saved correctly.');
+    $expected = ['source_field' => 'field_media_test_1', 'test_config_value' => 'Somewhere over the rainbow.'];
+    $this->assertSame($expected, $source->getConfiguration(), 'Submitted values were saved correctly.');
 
     // Try to save a NULL value.
     $form_state->setValue('test_config_value', NULL);
     $source->submitConfigurationForm($form, $form_state);
     $expected['test_config_value'] = NULL;
-    $this->assertEquals($expected, $source->getConfiguration(), 'Submitted values were saved correctly.');
+    $this->assertSame($expected, $source->getConfiguration(), 'Submitted values were saved correctly.');
 
     // Make sure that the config keys are determined correctly even if the
     // existing value is NULL.
     $form_state->setValue('test_config_value', 'Somewhere over the rainbow.');
     $source->submitConfigurationForm($form, $form_state);
     $expected['test_config_value'] = 'Somewhere over the rainbow.';
-    $this->assertEquals($expected, $source->getConfiguration(), 'Submitted values were saved correctly.');
+    $this->assertSame($expected, $source->getConfiguration(), 'Submitted values were saved correctly.');
 
     // Make sure that a non-relevant value will be skipped.
     $form_state->setValue('not_relevant', 'Should not be saved in the plugin.');
     $source->submitConfigurationForm($form, $form_state);
-    $this->assertEquals($expected, $source->getConfiguration(), 'Submitted values were saved correctly.');
+    $this->assertSame($expected, $source->getConfiguration(), 'Submitted values were saved correctly.');
   }
 
   /**