diff --git a/webservice/webservice.py b/webservice/webservice.py
index 23c5ce6ad77f258edfbc1cbba533d9505c5b08fe..f15aefbae606cf3d30067a398144e7ca6f8fa37a 100644
--- a/webservice/webservice.py
+++ b/webservice/webservice.py
@@ -617,7 +617,7 @@ async def wait_on_transfer(
 
 async def wait_transfers(
     mdc: MetadataClient,
-    runs: List[int],
+    runs: List[str],
     proposal: str,
     cycle: int,
     instrument: str,
@@ -638,7 +638,7 @@ async def wait_transfers(
 
     coros = []
     for run in runs:
-        run_dir = (in_folder / f"r{run:04d}")
+        run_dir = (in_folder / f"r{int(run):04d}")
         coros.append(wait_on_transfer(mdc, run, proposal, run_dir))
 
     try: