diff --git a/biliarchiver/rest_api/main.py b/biliarchiver/rest_api/main.py
index 80a1cb0..e4e2ce5 100644
--- a/biliarchiver/rest_api/main.py
+++ b/biliarchiver/rest_api/main.py
@@ -126,6 +126,8 @@ async def add_from_source(source_type: str, source_id: int):
         source_id = int(source_id)
     except ValueError:
         raise HTTPException(status_code=400, detail="Invalid source id")
+    
+    source_id = str(source_id)
 
     cmd_mapping = {
         "user": ["biliarchiver", "get", "--up-videos", source_id],