diff --git a/core/modules/file/src/Plugin/Validation/Constraint/FileValidationConstraintValidator.php b/core/modules/file/src/Plugin/Validation/Constraint/FileValidationConstraintValidator.php
index f100504..1b1e6a3 100644
--- a/core/modules/file/src/Plugin/Validation/Constraint/FileValidationConstraintValidator.php
+++ b/core/modules/file/src/Plugin/Validation/Constraint/FileValidationConstraintValidator.php
@@ -2,6 +2,7 @@
 
 namespace Drupal\file\Plugin\Validation\Constraint;
 
+use Drupal\Component\Utility\Bytes;
 use Symfony\Component\Validator\Constraint;
 use Symfony\Component\Validator\ConstraintValidator;
 
@@ -20,8 +21,9 @@ public function validate($value, Constraint $constraint) {
     $validators = $value->getUploadValidators();
 
     // Always respect the configured maximum file size.
-    if ($max_filesize = $value->getFieldDefinition()->getSetting('max_filesize')) {
-      $validators['file_validate_size'] = $max_filesize;
+    if ($max_filesize = Bytes::toInt($value->getFieldDefinition()->getSetting('max_filesize'))) {
+      // Always respect the configured maximum file size.
+      $validators['file_validate_size'] = [$max_filesize];
     }
     else {
       // Do not validate the file size if it is not set explicitly.