diff --git a/backend/package/yuxi/services/conversation_service.py b/backend/package/yuxi/services/conversation_service.py
index cc5ddaff..f5dca488 100644
--- a/backend/package/yuxi/services/conversation_service.py
+++ b/backend/package/yuxi/services/conversation_service.py
@@ -83,7 +83,7 @@ async def _convert_upload_to_markdown(upload: UploadFile) -> ConversionResult:
 
     try:
         file_size = await _write_upload_to_disk(upload, temp_path)
-        markdown = await Parser.aparse(str(temp_path), source_type="file")
+        markdown = await Parser.aparse(str(temp_path))
         markdown, truncated = _truncate_markdown(markdown)
         return ConversionResult(
             file_id=uuid.uuid4().hex,
@@ -94,7 +94,7 @@ async def _convert_upload_to_markdown(upload: UploadFile) -> ConversionResult:
             truncated=truncated,
         )
     except Exception as exc:  # noqa: BLE001
-        logger.error("Attachment conversion failed: %s", exc)
+        logger.error(f"Attachment conversion failed: {exc}")
         raise
 
 
diff --git a/backend/test/test_conversation_service_attachment_state.py b/backend/test/test_conversation_service_attachment_state.py
index 7d85d5b3..c133329e 100644
--- a/backend/test/test_conversation_service_attachment_state.py
+++ b/backend/test/test_conversation_service_attachment_state.py
@@ -123,8 +123,7 @@ async def test_convert_upload_to_markdown_returns_conversion_result(
     tmp_path,
     monkeypatch: pytest.MonkeyPatch,
 ):
-    async def _fake_aparse(source: str, params=None, source_type: str = "file") -> str:
-        assert source_type == "file"
+    async def _fake_aparse(source: str, params=None) -> str:
         return "converted markdown"
 
     monkeypatch.setattr(svc, "_ensure_workdir", lambda: tmp_path)
@@ -147,8 +146,7 @@ async def test_convert_upload_to_markdown_truncates_content(
     tmp_path,
     monkeypatch: pytest.MonkeyPatch,
 ):
-    async def _fake_aparse(source: str, params=None, source_type: str = "file") -> str:
-        assert source_type == "file"
+    async def _fake_aparse(source: str, params=None) -> str:
         return "x" * (svc.MAX_ATTACHMENT_MARKDOWN_CHARS + 200)
 
     monkeypatch.setattr(svc, "_ensure_workdir", lambda: tmp_path)