diff --git a/core/modules/file/src/Plugin/Field/FieldType/FileItem.php b/core/modules/file/src/Plugin/Field/FieldType/FileItem.php
index 99bfae4b27..f057149fb8 100644
--- a/core/modules/file/src/Plugin/Field/FieldType/FileItem.php
+++ b/core/modules/file/src/Plugin/Field/FieldType/FileItem.php
@@ -179,7 +179,7 @@ public function fieldSettingsForm(array $form, FormStateInterface $form_state) {
       '#type' => 'textfield',
       '#title' => t('Maximum upload size'),
       '#default_value' => $settings['max_filesize'],
-      '#description' => t('Enter a value like "512" (bytes), "80 KB" (kilobytes) or "50 MB" (megabytes) in order to restrict the allowed file size. If left empty the file sizes will be limited only by PHP\'s maximum post and file upload sizes (current limit <strong>%limit</strong>).', ['%limit' => format_size(Environment::getUploadMaxSize())]),
+      '#description' => t('Enter a value like "512" (bytes), "80 KB" (kilobytes) or "50 MB" (megabytes) in order to restrict the allowed file size. If left empty the file sizes could be limited only by PHP\'s maximum post and file upload sizes (current limit <strong>%limit</strong>).', ['%limit' => format_size(file_upload_max_size())]),
       '#size' => 10,
       '#element_validate' => [[static::class, 'validateMaxFilesize']],
       '#weight' => 5,
diff --git a/core/modules/file/src/Plugin/Validation/Constraint/FileValidationConstraintValidator.php b/core/modules/file/src/Plugin/Validation/Constraint/FileValidationConstraintValidator.php
index a6da920c66..2c8d8ddf67 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;
 
@@ -23,6 +24,16 @@ public function validate($value, Constraint $constraint) {
     $file = $target->getValue();
     // Get the validators.
     $validators = $value->getUploadValidators();
+
+    // Always respect the configured maximum file size.
+    if ($max_filesize = Bytes::toInt($value->getFieldDefinition()->getSetting('max_filesize'))) {
+      $validators['file_validate_size'] = [$max_filesize];
+    }
+    else {
+      // Do not validate the file size if it is not set explicitly.
+      unset($validators['file_validate_size']);
+    }
+
     // Checks that a file meets the criteria specified by the validators.
     if ($errors = file_validate($file, $validators)) {
       foreach ($errors as $error) {