diff --git a/main.ts b/main.ts
index f6a28df..1dd8591 100644
--- a/main.ts
+++ b/main.ts
@@ -110,6 +110,10 @@ const options = {
       if (args.values.download === "all") {
         books.push(...(await library.getBooks()));
       } else {
+        if (URL.canParse(args.values.download!)) {
+          await library.add(args.values.download!);
+        }
+
         const book = await library.get(Number(args.values.download!));
 
         if (!book) {