diff -u b/core/modules/file/src/Entity/File.php b/core/modules/file/src/Entity/File.php
--- b/core/modules/file/src/Entity/File.php
+++ b/core/modules/file/src/Entity/File.php
@@ -253,7 +253,7 @@
       ->setDescription(t('The URI to access the file (either local or remote).'))
       ->setSetting('max_length', 255)
       ->setSetting('case_sensitive', TRUE)
-      ->addConstraint('FileUri');
+      ->addConstraint('FileUriUnique');
 
     $fields['filemime'] = BaseFieldDefinition::create('string')
       ->setLabel(t('File MIME type'))
diff -u b/core/modules/file/src/Plugin/Validation/Constraint/FileUriUnique.php b/core/modules/file/src/Plugin/Validation/Constraint/FileUriUnique.php
--- b/core/modules/file/src/Plugin/Validation/Constraint/FileUriUnique.php
+++ b/core/modules/file/src/Plugin/Validation/Constraint/FileUriUnique.php
@@ -13,7 +13,7 @@
  * Supports validating file URIs.
  *
  * @Plugin(
- *   id = "FileUri",
+ *   id = "FileUriUnique",
  *   label = @Translation("File URI", context = "Validation")
  * )
  */