diff --git a/lib/tests/test_mnemonic.py b/lib/tests/test_mnemonic.py
new file mode 100644
index 00000000..541e33f3
--- /dev/null
+++ b/lib/tests/test_mnemonic.py
@@ -0,0 +1,34 @@
+import unittest
+from lib import mnemonic
+from lib import old_mnemonic
+
+class Test_NewMnemonic(unittest.TestCase):
+
+    def test_prepare_seed(self):
+        seed = 'foo BAR Baz'
+        self.assertEquals(mnemonic.prepare_seed(seed), 'foo bar baz')
+
+    def test_to_seed(self):
+        seed = mnemonic.Mnemonic.mnemonic_to_seed(mnemonic='foobar', passphrase='none')
+        self.assertEquals(seed.encode('hex'),
+                          '741b72fd15effece6bfe5a26a52184f66811bd2be363190e07a42cca442b1a5b'
+                          'b22b3ad0eb338197287e6d314866c7fba863ac65d3f156087a5052ebc7157fce')
+
+    def test_random_seeds(self):
+        iters = 10
+        m = mnemonic.Mnemonic(lang='en')
+        for _ in range(iters):
+            seed = m.make_seed()
+            self.assertTrue(m.check_seed(seed, custom_entropy=1))
+            i = m.mnemonic_decode(seed)
+            self.assertEquals(m.mnemonic_encode(i), seed)
+
+
+class Test_OldMnemonic(unittest.TestCase):
+
+    def test(self):
+        seed = '8edad31a95e7d59f8837667510d75a4d'
+        result = old_mnemonic.mn_encode(seed)
+        words = 'hardly point goal hallway patience key stone difference ready caught listen fact'
+        self.assertEquals(result, words.split())
+        self.assertEquals(old_mnemonic.mn_decode(result), seed)