diff --git a/weed/s3api/s3api_object_copy_handlers.go b/weed/s3api/s3api_object_copy_handlers.go
index b18ab329c..b8fb3f6a4 100644
--- a/weed/s3api/s3api_object_copy_handlers.go
+++ b/weed/s3api/s3api_object_copy_handlers.go
@@ -113,7 +113,7 @@ func (s3a *S3ApiServer) CopyObjectPartHandler(w http.ResponseWriter, r *http.Req
 	}
 
 	// check partID with maximum part ID for multipart objects
-	if partID > 10000 {
+	if partID > globalMaxPartID {
 		writeErrorResponse(w, ErrInvalidMaxParts, r.URL)
 		return
 	}