diff --git a/src/index.ts b/src/index.ts
index b124190..a4d6833 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -42,10 +42,15 @@ async function putArchive(request: Request, key: string, env: Env): Promise<Resp
   if (!Number.isFinite(length) || length <= 0 || length > MAX_ARCHIVE_OBJECT_BYTES) return json({ error: "content-length required, ≤ 200 MiB" }, 413);
   if (request.body === null) return json({ error: "empty body" }, 400);
   const bucket = bucketFor(key, env);
-  const object = await bucket.put(key, request.body, {
-    httpMetadata: { contentType: key.endsWith(".json") ? "application/json" : "application/vnd.apache.parquet" },
-  });
-  return json({ key, size: object.size, etag: object.httpEtag, bucket: bucket === env.PRIVATE ? "private" : "public" });
+  try {
+    const object = await bucket.put(key, request.body, {
+      httpMetadata: { contentType: key.endsWith(".json") ? "application/json" : "application/vnd.apache.parquet" },
+    });
+    return json({ key, size: object.size, etag: object.httpEtag, bucket: bucket === env.PRIVATE ? "private" : "public" });
+  } catch (err) {
+    // an R2 hiccup surfaces here as a 503 with the message, not a bare 1101; the drain retries on 5xx
+    return json({ error: err instanceof Error ? err.message : "put failed" }, 503);
+  }
 }
 
 const MAX_BODY_BYTES = 8 << 20;