diff --git a/src/llamafactory/api/chat.py b/src/llamafactory/api/chat.py
index 1f0c1e95..74b56f73 100644
--- a/src/llamafactory/api/chat.py
+++ b/src/llamafactory/api/chat.py
@@ -106,7 +106,7 @@ def _process_request(
                     input_messages.append({"role": ROLE_MAPPING[message.role], "content": input_item.text})
                 else:
                     image_url = input_item.image_url.url
-                    if re.match("^data:image\/(png|jpg|jpeg|gif|bmp);base64,(.+)$", data_url):
+                    if re.match("^data:image\/(png|jpg|jpeg|gif|bmp);base64,(.+)$", image_url):
                         image_data = base64.b64decode(image_url.split(",", maxsplit=1)[1])
                         image_path = io.BytesIO(image_data)
                     elif os.path.isfile(image_url):  # local file