diff --git a/core/modules/book/src/Plugin/Validation/Constraint/BookOutlineConstraintValidator.php b/core/modules/book/src/Plugin/Validation/Constraint/BookOutlineConstraintValidator.php
index 7adb0a7..dbf2417 100644
--- a/core/modules/book/src/Plugin/Validation/Constraint/BookOutlineConstraintValidator.php
+++ b/core/modules/book/src/Plugin/Validation/Constraint/BookOutlineConstraintValidator.php
@@ -52,12 +52,18 @@ public function validate($entity, Constraint $constraint) {
           ->setInvalidValue($entity)
           ->addViolation();
       }
-      elseif ($entity->book['pid'] != $original['pid']) {
+      if ($entity->book['pid'] != $original['pid']) {
         $this->context->buildViolation($constraint->message)
           ->atPath('book.pid')
           ->setInvalidValue($entity)
           ->addViolation();
       }
+      if ($entity->book['weight'] != $original['weight']) {
+        $this->context->buildViolation($constraint->message)
+          ->atPath('book.weight')
+          ->setInvalidValue($entity)
+          ->addViolation();
+      }
     }
   }