diff -u b/core/tests/Drupal/KernelTests/Core/Entity/ContentEntityChangedTest.php b/core/tests/Drupal/KernelTests/Core/Entity/ContentEntityChangedTest.php
--- b/core/tests/Drupal/KernelTests/Core/Entity/ContentEntityChangedTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/ContentEntityChangedTest.php
@@ -137,6 +137,8 @@
       'Changed time of the German translation did change.'
     );
 
+    $this->assertEquals($entity->getChangedTime(), $german->getChangedTime(), 'When editing a non-translatable field the updated changed time is equal across all translations.');
+
     $changed_en = $entity->getChangedTime();
     $changed_de = $german->getChangedTime();