diff --git a/tests/bip0039_fixtures.py b/tests/bip0039_fixtures.py
new file mode 100644
index 0000000..d9440b5
--- /dev/null
+++ b/tests/bip0039_fixtures.py
@@ -0,0 +1,74 @@
+import pytest
+import random
+
+
+#@pytest.fixture
+#def gen_entropy(bit_size):
+    #rnd = random.systemRandom(123456)
+    #return rnd.randint(0, 255)
+
+@pytest.fixture
+def mnemonic_128():
+    return ['nurse', 'fortune', 'immune', 'rapid', 'trash',
+            'very', 'turkey', 'romance', 'short', 'clutch', 'hunt', 'wait']
+
+@pytest.fixture
+def mnemonic_160():
+    return ['mail', 'paddle', 'wine', 'fox', 'various', 'absent',
+            'manage', 'divert', 'awful', 'push', 'mystery',
+            'mule', 'arrest', 'lawsuit', 'orient']
+
+@pytest.fixture
+def mnemonic_192():
+    return ['craft', 'first', 'champion', 'border', 'rely',
+            'dance', 'tag', 'voyage', 'category', 'orbit',
+            'hungry', 'caught', 'occur', 'wonder', 'history',
+            'jacket', 'first', 'plunge']
+
+@pytest.fixture
+def mnemonic_224():
+    return ['liberty', 'family', 'lobster', 'omit', 'glide',
+            'vague', 'market', 'cancel', 'exotic', 'jazz',
+            'sausage', 'elite', 'tuition', 'grief', 'typical',
+            'hobby', 'local', 'impact', 'leopard', 'basic', 'obscure']
+
+@pytest.fixture
+def mnemonic_256():
+    return ['neck', 'adjust', 'town', 'ticket', 'sunset', 'pulse',
+            'space', 'dolphin', 'farm', 'absent', 'cat', 'adult',
+            'erupt', 'student', 'globe', 'tooth', 'tackle', 'group',
+            'sponsor', 'dice', 'add', 'maid', 'illegal', 'major']
+
+@pytest.fixture
+def entropy_128():
+    return b'\x97\x8bq\xc6\xd8\xfew\xe5\xfa\xad\xdc\xc6\xc5\x91\xbd\xfb'
+
+@pytest.fixture
+def entropy_160():
+    return b'\x863\xdb\xee./\x18\x01a\xb9\xfe\x10\xb5\xd6I\xc8\xa0\xc6\xfcg'
+
+@pytest.fixture
+def entropy_192():
+    return b'2\n\xec\x98\x0c\xebVn\xb7O\xb0$3}\xbd\x129\x8d\xfa\x1b\x0b\xb8Wt'
+
+@pytest.fixture
+def entropy_224():
+    return b'\x80\xeaR\x0c\xcd61\xe1b\t\tP\x0e\xee\xfe\xa4\x0e\xa2\xcd:\xfbb\x83N:\x01\t\x89'
+
+@pytest.fixture
+def entropy_256():
+    return b'\x93\xa0s\x99p\xdd\x99[4\x12\x06S \x14\x8f\x01\xe4\xcf\xae\xd8\xd7&\xdd\x0c\xdfI\x9e\xb03\x0c\x1cD'
+
+
+@pytest.yield_fixture
+def wordlist():
+    f = None
+    def select_wordlist(filename):
+        nonlocal f
+        assert f is None
+        f = open(filename)
+        return f
+    yield select_wordlist
+    if f is not None:
+        f.close()
+        
diff --git a/tests/test_bip0039.py b/tests/test_bip0039.py
new file mode 100644
index 0000000..4ae3587
--- /dev/null
+++ b/tests/test_bip0039.py
@@ -0,0 +1,113 @@
+import os
+import random
+import hashlib
+import hmac
+from binascii import hexlify, unhexlify
+from pybtc.hdwallet import *
+
+
+
+def test_recovery_from_passphrase_12(entropy_128, mnemonic_128):
+    passphrase = ' '.join(mnemonic_128)
+    entropy = mnemonic2bytes(passphrase, 'english')
+    assert entropy == entropy_128
+
+
+def test_recovery_from_passphrase_15(entropy_160, mnemonic_160):
+    passphrase = ' '.join(mnemonic_160)
+    entropy = mnemonic2bytes(passphrase, 'english')
+    assert entropy == entropy_160
+
+
+def test_recovery_from_passphrase_18(entropy_192, mnemonic_192):
+    passphrase = ' '.join(mnemonic_192)
+    entropy = mnemonic2bytes(passphrase, 'english')
+    assert entropy == entropy_192
+
+
+def test_recovery_from_passphrase_21(entropy_224, mnemonic_224):
+    passphrase = ' '.join(mnemonic_224)
+    entropy = mnemonic2bytes(passphrase, 'english')
+    assert entropy == entropy_224
+
+
+def test_recovery_from_passphrase_24(entropy_256, mnemonic_256):
+    passphrase = ' '.join(mnemonic_256)
+    entropy = mnemonic2bytes(passphrase, 'english')
+    assert entropy == entropy_256
+
+
+def test_create_mnemonic(entropy_128, entropy_160, entropy_192, entropy_224, entropy_256):
+    mnemonic = create_mnemonic(entropy_128, 'english')
+    assert len(mnemonic) == 12
+
+    mnemonic = create_mnemonic(entropy_160, 'english')
+    assert len(mnemonic) == 15
+
+    mnemonic = create_mnemonic(entropy_192, 'english')
+    assert len(mnemonic) == 18
+
+    mnemonic = create_mnemonic(entropy_224, 'english')
+    assert len(mnemonic) == 21
+    
+    mnemonic = create_mnemonic(entropy_256, 'english')
+    assert len(mnemonic) == 24
+
+
+def test_create_wordlist():
+    wordlist_en = create_wordlist('english')
+    wordlist_fr = create_wordlist('french')
+    wordlist_it = create_wordlist('italian')
+    wordlist_sp = create_wordlist('spanish')
+    assert 'abandon' in wordlist_en
+    assert 'abaisser' in wordlist_fr
+    assert 'abaco' in wordlist_it
+    assert 'ábaco' in wordlist_sp
+
+
+
+def test_create_passphrase():
+    passphrase = create_passphrase(128, 'english')
+    assert len(passphrase.split()) == 12
+    
+    passphrase = create_passphrase(160, 'english')
+    assert len(passphrase.split()) == 15
+    
+    passphrase = create_passphrase(192, 'english')
+    assert len(passphrase.split()) == 18
+    
+    passphrase = create_passphrase(224, 'english')
+    assert len(passphrase.split()) == 21
+    
+    passphrase = create_passphrase(256, 'english')
+    assert len(passphrase.split()) == 24
+
+
+def test_add_checksum(entropy_128, entropy_160, entropy_192, entropy_224, entropy_256):
+    ent_add_chksum = add_checksum(entropy_128)
+    ent_hash = hashlib.sha256(entropy_128).hexdigest()
+    fb = unhexlify(ent_hash)[0]
+    assert (fb >> 4) & ent_add_chksum
+
+    ent_add_chksum = add_checksum(entropy_160)
+    ent_hash = hashlib.sha256(entropy_160).hexdigest()
+    fb = unhexlify(ent_hash)[0]
+    assert (fb >> 3) & ent_add_chksum
+
+    ent_add_chksum = add_checksum(entropy_192)
+    ent_hash = hashlib.sha256(entropy_192).hexdigest()
+    fb = unhexlify(ent_hash)[0]
+    assert (fb >> 2) & ent_add_chksum
+
+    ent_add_chksum = add_checksum(entropy_224)
+    ent_hash = hashlib.sha256(entropy_224).hexdigest()
+    fb = unhexlify(ent_hash)[0]
+    assert (fb >> 1) & ent_add_chksum
+
+    ent_add_chksum = add_checksum(entropy_256)
+    ent_hash = hashlib.sha256(entropy_256).hexdigest()
+    fb = unhexlify(ent_hash)[0]
+    assert fb & ent_add_chksum
+
+
+