diff --git a/demos/supabase-todolist-drift/lib/attachments/queue.dart b/demos/supabase-todolist-drift/lib/attachments/queue.dart
index 63d903ac..230cb855 100644
--- a/demos/supabase-todolist-drift/lib/attachments/queue.dart
+++ b/demos/supabase-todolist-drift/lib/attachments/queue.dart
@@ -68,7 +68,7 @@ class PhotoAttachmentQueue extends AbstractAttachmentQueue {
   }
 
   @override
-  StreamSubscription<void> watchIds({String fileExtension = 'jpg'}) {
+  StreamSubscription<void> watchIds({String? fileExtension}) {
     log.info('Watching photos in $todosTable...');
     return db.watch('''
       SELECT photo_id FROM $todosTable
diff --git a/demos/supabase-todolist/lib/attachments/queue.dart b/demos/supabase-todolist/lib/attachments/queue.dart
index 2a8dd9ca..d2fc4f64 100644
--- a/demos/supabase-todolist/lib/attachments/queue.dart
+++ b/demos/supabase-todolist/lib/attachments/queue.dart
@@ -68,7 +68,7 @@ class PhotoAttachmentQueue extends AbstractAttachmentQueue {
   }
 
   @override
-  StreamSubscription<void> watchIds({String fileExtension = 'jpg'}) {
+  StreamSubscription<void> watchIds({String? fileExtension}) {
     log.info('Watching photos in $todosTable...');
     return db.watch('''
       SELECT photo_id FROM $todosTable
diff --git a/packages/powersync_attachments_helper/README.md b/packages/powersync_attachments_helper/README.md
index dbd65bef..5de3a4ef 100644
--- a/packages/powersync_attachments_helper/README.md
+++ b/packages/powersync_attachments_helper/README.md
@@ -62,7 +62,7 @@ class PhotoAttachmentQueue extends AbstractAttachmentQueue {
   // This watcher will handle adding items to the queue based on
   // a users table element receiving a photoId
   @override
-  StreamSubscription<void> watchIds({String fileExtension = 'jpg'}) {
+  StreamSubscription<void> watchIds({String? fileExtension}) {
     return db.watch('''
       SELECT photo_id FROM users
       WHERE photo_id IS NOT NULL
diff --git a/packages/powersync_attachments_helper/example/getting_started.dart b/packages/powersync_attachments_helper/example/getting_started.dart
index 037046f0..858be3df 100644
--- a/packages/powersync_attachments_helper/example/getting_started.dart
+++ b/packages/powersync_attachments_helper/example/getting_started.dart
@@ -46,7 +46,7 @@ class PhotoAttachmentQueue extends AbstractAttachmentQueue {
   }
 
   @override
-  StreamSubscription<void> watchIds({String fileExtension = 'jpg'}) {
+  StreamSubscription<void> watchIds({String? fileExtension}) {
     return db.watch('''
       SELECT photo_id FROM users
       WHERE photo_id IS NOT NULL
diff --git a/packages/powersync_attachments_helper/lib/src/attachments_queue.dart b/packages/powersync_attachments_helper/lib/src/attachments_queue.dart
index 08dd48ce..f8e18ba0 100644
--- a/packages/powersync_attachments_helper/lib/src/attachments_queue.dart
+++ b/packages/powersync_attachments_helper/lib/src/attachments_queue.dart
@@ -41,6 +41,10 @@ abstract class AbstractAttachmentQueue {
   /// when the attachment queue is initialized.
   List<String>? subdirectories;
 
+  /// File extension to be used for the attachments queue
+  /// Can be left null if no extension is used or if extension is part of the filename
+  String? fileExtension;
+
   AbstractAttachmentQueue(
       {required this.db,
       required this.remoteStorage,
@@ -49,7 +53,8 @@ abstract class AbstractAttachmentQueue {
       this.onDownloadError,
       this.onUploadError,
       this.intervalInMinutes = 5,
-      this.subdirectories}) {
+      this.subdirectories,
+      this.fileExtension}) {
     attachmentsService = AttachmentsService(
         db, localStorage, attachmentDirectoryName, attachmentsQueueTableName);
     syncingService = SyncingService(
@@ -59,7 +64,7 @@ abstract class AbstractAttachmentQueue {
 
   /// Create watcher to get list of ID's from a table to be used for syncing in the attachment queue.
   /// Set the file extension if you are using a different file type
-  StreamSubscription<void> watchIds({String fileExtension = 'jpg'});
+  StreamSubscription<void> watchIds({String? fileExtension});
 
   /// Create a function to save files using the attachment queue
   Future<Attachment> saveFile(String fileId, int size);
@@ -82,7 +87,7 @@ abstract class AbstractAttachmentQueue {
       }
     }
 
-    watchIds();
+    watchIds(fileExtension: fileExtension);
     syncingService.watchAttachments();
     syncingService.startPeriodicSync(intervalInMinutes);
 
diff --git a/packages/powersync_attachments_helper/lib/src/local_storage_adapter.dart b/packages/powersync_attachments_helper/lib/src/local_storage_adapter.dart
index f12d3f35..d2bef3cc 100644
--- a/packages/powersync_attachments_helper/lib/src/local_storage_adapter.dart
+++ b/packages/powersync_attachments_helper/lib/src/local_storage_adapter.dart
@@ -5,6 +5,7 @@ import 'package:path_provider/path_provider.dart';
 /// Storage adapter for local storage
 class LocalStorageAdapter {
   Future<File> saveFile(String fileUri, Uint8List data) async {
+    await makeDir(fileUri);
     final file = File(fileUri);
     return await file.writeAsBytes(data);
   }
@@ -30,12 +31,13 @@ class LocalStorageAdapter {
   Future<void> makeDir(String fileUri) async {
     bool exists = await fileExists(fileUri);
     if (!exists) {
-      Directory newDirectory = Directory(fileUri);
-      await newDirectory.create(recursive: true);
+      Directory parentDirectories = File(fileUri).parent;
+      await parentDirectories.create(recursive: true);
     }
   }
 
   Future<void> copyFile(String sourceUri, String targetUri) async {
+    await makeDir(targetUri);
     File file = File(sourceUri);
     await file.copy(targetUri);
   }
diff --git a/packages/powersync_attachments_helper/lib/src/syncing_service.dart b/packages/powersync_attachments_helper/lib/src/syncing_service.dart
index 04897329..c055839a 100644
--- a/packages/powersync_attachments_helper/lib/src/syncing_service.dart
+++ b/packages/powersync_attachments_helper/lib/src/syncing_service.dart
@@ -165,11 +165,12 @@ class SyncingService {
   }
 
   /// Process ID's to be included in the attachment queue.
-  Future<void> processIds(List<String> ids, String fileExtension) async {
+  Future<void> processIds(List<String> ids, String? fileExtension) async {
     List<Attachment> attachments = List.empty(growable: true);
 
     for (String id in ids) {
-      String path = await getLocalUri('$id.$fileExtension');
+      String filename = fileExtension != null ? '$id.$fileExtension' : id;
+      String path = await getLocalUri(filename);
       File file = File(path);
       bool fileExists = await file.exists();
 
@@ -180,7 +181,7 @@ class SyncingService {
       log.info('Adding $id to queue');
       attachments.add(Attachment(
           id: id,
-          filename: '$id.$fileExtension',
+          filename: filename,
           state: AttachmentState.queuedDownload.index));
     }