diff --git a/CHANGELOG.md b/CHANGELOG.md
index ba09121..a3361a7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,9 @@
 
 * filepond: Rename `remove_on_null` to `allow_delete` for consistency with other
   form types.
+* symfony-bridge: Update `FileTransformer` to deal with situations where the
+  transformer is installed twice on the same form. For example, if
+  `FileTypeExtension` is active app-wide.
 
 ## 1.6.0
 
diff --git a/packages/file-symfony-bridge/src/Form/FileTransformer.php b/packages/file-symfony-bridge/src/Form/FileTransformer.php
index 72e3844..70163a7 100644
--- a/packages/file-symfony-bridge/src/Form/FileTransformer.php
+++ b/packages/file-symfony-bridge/src/Form/FileTransformer.php
@@ -38,6 +38,10 @@ public function transform($value): ?File
             return null;
         }
 
+        if ($value instanceof File) {
+            return $value;
+        }
+
         if (!$value instanceof FileInterface) {
             throw new TransformationFailedException(sprintf(
                 'Expecting "%s", but getting "%s" instead.',
@@ -61,6 +65,10 @@ public function reverseTransform(mixed $value): ?FileInterface
             return null;
         }
 
+        if ($value instanceof FileInterface) {
+            return $value;
+        }
+
         if (!$value instanceof File) {
             throw new TransformationFailedException(sprintf(
                 'Expecting "%s", but getting "%s" instead.',