diff --git a/nip06.test.js b/nip06.test.js
new file mode 100644
index 0000000..1e28412
--- /dev/null
+++ b/nip06.test.js
@@ -0,0 +1,15 @@
+/* eslint-env jest */
+const {nip06} = require('./lib/nostr.cjs')
+
+test('generate private key from a mnemonic', async () => {
+  const mnemonic = 'zoo zoo zoo zoo zoo zoo zoo zoo zoo zoo zoo wrong'
+  const privateKey = nip06.privateKeyFromSeedWords(mnemonic)
+  expect(privateKey).toEqual('c26cf31d8ba425b555ca27d00ca71b5008004f2f662470f8c8131822ec129fe2')
+})
+
+test('generate private key from a mnemonic and passphrase', async () => {
+  const mnemonic = 'zoo zoo zoo zoo zoo zoo zoo zoo zoo zoo zoo wrong'
+  const passphrase = '123'
+  const privateKey = nip06.privateKeyFromSeedWords(mnemonic, passphrase)
+  expect(privateKey).toEqual('55a22b8203273d0aaf24c22c8fbe99608e70c524b17265641074281c8b978ae4')
+})