diff --git a/example_file_drop.py b/example_file_drop.py
index 23eab85..f5eba8d 100644
--- a/example_file_drop.py
+++ b/example_file_drop.py
@@ -14,7 +14,7 @@ async def main_page():
     # Example 1: Multiple files with content
     uploaded_files = ui.column().classes('w-full mt-4')
 
-    def handle_multiple_files(file: FileData):
+    async def handle_multiple_files(file: FileData):
         with uploaded_files:
             with ui.card().classes('p-2 mb-2'):
                 ui.label(f"📄 {file['name']}").classes('font-medium')
@@ -26,7 +26,7 @@ async def main_page():
         on_upload=handle_multiple_files,
         multiple=True,
         accept='.pdf,.docx,.txt,.jpg,.png',
-        max_size=5  # 5MB limit
+        max_size=15  # 5MB limit
     ).classes('w-full max-w-xl mx-auto')
 
     ui.separator().classes('my-8')
@@ -72,7 +72,7 @@ async def main_page():
     # Example 4: Image drop with preview
     image_preview = ui.column().classes('w-full mt-4')
 
-    def handle_image(img: ImageData):
+    async def handle_image(img: ImageData):
         print(f"Image uploaded: {img['image'].format}, Size: {img['size']}")
         image_preview.clear()
         with image_preview:
diff --git a/src/niceguiex/components/file_drop.py b/src/niceguiex/components/file_drop.py
index 6972034..85b08ac 100644
--- a/src/niceguiex/components/file_drop.py
+++ b/src/niceguiex/components/file_drop.py
@@ -108,7 +108,7 @@ class FileDrop(ui.element):
             }})();
         ''')
 
-    def _handle_upload(self, e):
+    async def _handle_upload(self, e):
         """Handle uploaded files"""
         if not self.on_upload_callback:
             return
@@ -116,12 +116,12 @@ class FileDrop(ui.element):
         # Process single file upload
         if hasattr(e, 'content'):
             print('content')
-            file_data = self._process_file(e)
+            file_data = await self._process_file(e)
             if file_data:
                 # For single file mode, return the dict directly
-                self.on_upload_callback(file_data)
+                await self.on_upload_callback(file_data)
 
-    def _process_file(self, file_obj) -> FileData | None:
+    async def _process_file(self, file_obj) -> FileData | None:
         """Process a single file object"""
         if not hasattr(file_obj, 'content'):
             return None
@@ -175,19 +175,19 @@ class ImageDrop(FileDrop):
             *args, **kwargs
         )
 
-    def _handle_image_upload(self, data: FileData):
+    async def _handle_image_upload(self, data: FileData):
         """Convert file data to PIL Images before calling user callback"""
         if self._user_callback:
             if isinstance(data, list) and len(data) == 1:
                 img = Image.open(io.BytesIO(data[0]['content']))
-                self._user_callback(img)
+                await self._user_callback(img)
             elif isinstance(data, list):
                 # Multiple images - convert each to PIL Image
                 images = []
                 for file_data in data:
                     img = Image.open(io.BytesIO(file_data['content']))
                     images.append(img)
-                self._user_callback(images)
+                await self._user_callback(images)
             else:
                 # Single image - convert to PIL Image
                 image_data: ImageData = {'name': data['name'],
@@ -195,4 +195,4 @@ class ImageDrop(FileDrop):
                                          'file_type': data['file_type'],
                                          'image': Image.open(io.BytesIO(data['content']))}
                 # img = Image.open(io.BytesIO(data['content']))
-                self._user_callback(image_data)
+                await self._user_callback(image_data)