diff --git a/core/lib/Drupal/Core/Entity/Plugin/Validation/Constraint/EntityUntranslatableFieldsConstraint.php b/core/lib/Drupal/Core/Entity/Plugin/Validation/Constraint/EntityUntranslatableFieldsConstraint.php
index 0044b6b4fb4..bb1a924d71c 100644
--- a/core/lib/Drupal/Core/Entity/Plugin/Validation/Constraint/EntityUntranslatableFieldsConstraint.php
+++ b/core/lib/Drupal/Core/Entity/Plugin/Validation/Constraint/EntityUntranslatableFieldsConstraint.php
@@ -15,6 +15,7 @@ use Symfony\Component\Validator\Constraint;
  */
 class EntityUntranslatableFieldsConstraint extends Constraint {
 
-  public $message = 'Non translatable fields can only be changed when updating the current revision or the original language.';
+  public $defaultRevisionMessage = 'Non-translatable fields can only be changed when updating the current revision.';
+  public $defaultTranslationMessage = 'Non-translatable fields can only be changed when updating the original language.';
 
 }
diff --git a/core/lib/Drupal/Core/Entity/Plugin/Validation/Constraint/EntityUntranslatableFieldsConstraintValidator.php b/core/lib/Drupal/Core/Entity/Plugin/Validation/Constraint/EntityUntranslatableFieldsConstraintValidator.php
index 6ac7d034b95..5b1ad1f5c99 100644
--- a/core/lib/Drupal/Core/Entity/Plugin/Validation/Constraint/EntityUntranslatableFieldsConstraintValidator.php
+++ b/core/lib/Drupal/Core/Entity/Plugin/Validation/Constraint/EntityUntranslatableFieldsConstraintValidator.php
@@ -49,10 +49,14 @@ class EntityUntranslatableFieldsConstraintValidator extends ConstraintValidator
    */
   public function validate($entity, Constraint $constraint) {
     /** @var \Drupal\Core\Entity\ContentEntityInterface $entity */
+    /** @var \Drupal\Core\Entity\Plugin\Validation\Constraint\EntityUntranslatableFieldsConstraint $constraint */
 
-    // Untranslatable field restrictions apply only to pending revisions of
-    // multilingual entities.
-    if ($entity->isNew() || $entity->isDefaultRevision() || !$entity->isTranslatable() || !$entity->getEntityType()->isRevisionable()) {
+    // Untranslatable field restrictions apply only to revisions of multilingual
+    // entities.
+    if ($entity->isNew() || !$entity->isTranslatable() || !$entity->getEntityType()->isRevisionable()) {
+      return;
+    }
+    if ($entity->isDefaultRevision() && !$entity->isDefaultTranslationAffectedOnly()) {
       return;
     }
 
@@ -63,18 +67,20 @@ class EntityUntranslatableFieldsConstraintValidator extends ConstraintValidator
     // a pending revision contains only one affected translation. Even in this
     // case, multiple translations would be affected in a single revision, if we
     // allowed changes to untranslatable fields while editing non-default
-    // translations, so that is forbidden too.
+    // translations, so that is forbidden too. For the same reason, when changes
+    // to untranslatable fields affect all translations, we can only allow them
+    // in default revisions.
     if ($this->hasUntranslatableFieldsChanges($entity)) {
       if ($entity->isDefaultTranslationAffectedOnly()) {
         foreach ($entity->getTranslationLanguages(FALSE) as $langcode => $language) {
           if ($entity->getTranslation($langcode)->hasTranslationChanges()) {
-            $this->context->addViolation($constraint->message);
+            $this->context->addViolation($constraint->defaultTranslationMessage);
             break;
           }
         }
       }
       else {
-        $this->context->addViolation($constraint->message);
+        $this->context->addViolation($constraint->defaultRevisionMessage);
       }
     }
   }
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/EntityDecoupledTranslationRevisionsTest.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityDecoupledTranslationRevisionsTest.php
index d5cc5330e65..cc3474575f4 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityDecoupledTranslationRevisionsTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityDecoupledTranslationRevisionsTest.php
@@ -234,6 +234,7 @@ class EntityDecoupledTranslationRevisionsTest extends EntityKernelTestBase {
         ['en', TRUE, TRUE],
         ['it', FALSE, TRUE, FALSE],
         ['en', FALSE, TRUE],
+        ['it', TRUE, TRUE, FALSE],
         ['it', FALSE],
         ['it', TRUE],
         ['en', TRUE, TRUE],
@@ -492,6 +493,35 @@ class EntityDecoupledTranslationRevisionsTest extends EntityKernelTestBase {
     return call_user_func_array('sprintf', $params);
   }
 
+  /**
+   * Checks that changes to multiple translations are handled correctly.
+   *
+   * @covers ::createRevision
+   * @covers \Drupal\Core\Entity\Plugin\Validation\Constraint\EntityUntranslatableFieldsConstraintValidator::validate
+   */
+  public function testMultipleTranslationChanges() {
+    // Configure the untranslatable fields edit mode.
+    $this->state->set('entity_test.untranslatable_fields.default_translation_affected', TRUE);
+    $this->bundleInfo->clearCachedBundles();
+
+    $entity = EntityTestMulRev::create();
+    $entity->get('name')->value = 'Test 1.1 EN';
+    $entity->get('non_mul_field')->value = 'Test 1.1';
+    $this->storage->save($entity);
+
+    /** @var \Drupal\Core\Entity\ContentEntityInterface $revision */
+    $revision = $this->storage->createRevision($entity->addTranslation('it'));
+    $revision->get('name')->value = 'Test 1.2 IT';
+    $this->storage->save($revision);
+
+    $revision = $this->storage->createRevision($revision->getTranslation('en'), FALSE);
+    $revision->get('non_mul_field')->value = 'Test 1.3';
+    $revision->getTranslation('it')->get('name')->value = 'Test 1.3 IT';
+    $violations = $revision->validate();
+    $this->assertCount(1, $violations);
+    $this->assertEquals('Non-translatable fields can only be changed when updating the original language.', $violations[0]->getMessage());
+  }
+
   /**
    * Tests that internal properties are preserved while creating a new revision.
    */