diff --git a/src/utils/bolt11.test.ts b/src/utils/bolt11.test.ts
new file mode 100644
index 00000000..9a9d1238
--- /dev/null
+++ b/src/utils/bolt11.test.ts
@@ -0,0 +1,19 @@
+import { assertEquals } from '@std/assert';
+import { getAmount } from '@/utils/bolt11.ts';
+
+Deno.test('Invoice is invalid', () => {
+  assertEquals(getAmount('hello'), undefined);
+});
+
+Deno.test('Invoice is undefined', () => {
+  assertEquals(getAmount(undefined), undefined);
+});
+
+Deno.test('Amount is 200000', () => {
+  assertEquals(
+    getAmount(
+      'lnbc2u1pn8qatypp5dweqaltlry2vgpxxyc0puxnc50335yznevj2g46wrhfm2694lhgqhp576ekte7lhhtsxdk6tfvkpyp8gdk2xccmuccdxwjd0fqdh34wfseqcqzzsxqyz5vqsp5n44zva7xndawg5l2r9d85v0tszwejtfzkc7v90d6c7d3nsdt0qds9qxpqysgqx2v2artsxmnfkpapdm9f5pahjs8etlpe7kcjue2kffhjg3jrtearstjvenr6lxzhpw3es4hpchzzeet7ul88elurfmvr9v94v0655rgpy7m7r5',
+    ),
+    '200000',
+  );
+});