diff --git a/test/test_commit.py b/test/test_commit.py
index 0884364..35ec65f 100644
--- a/test/test_commit.py
+++ b/test/test_commit.py
@@ -68,7 +68,9 @@ class CommitTest(utils.BareRepoTestCase):
         repo = self.repo
         message = 'New commit.\n\nMessage with non-ascii chars: ééé.\n'
         committer = Signature('John Doe', 'jdoe@example.com', 12346, 0)
-        author = Signature('J. David Ibáñez', 'jdavid@example.com', 12345, 0)
+        author = Signature(
+            'J. David Ibáñez', 'jdavid@example.com', 12345, 0,
+            encoding='utf-8')
         tree = '967fce8df97cc71722d3c2a5930ef3e6f1d27b12'
         tree_prefix = tree[:5]
         too_short_prefix = tree[:3]
diff --git a/test/test_signature.py b/test/test_signature.py
index 2b59c29..2917a49 100644
--- a/test/test_signature.py
+++ b/test/test_signature.py
@@ -37,26 +37,29 @@ from .utils import NoRepoTestCase
 class SignatureTest(NoRepoTestCase):
 
     def test_default(self):
-        signature = Signature('Foo Ibáñez', 'foo@example.com', 1322174594, 60)
+        signature = Signature(
+            'Foo', 'foo@example.com', 1322174594, 60)
         encoding = signature._encoding
-        self.assertEqual(encoding, 'utf-8')
+        self.assertEqual(encoding, 'ascii')
         self.assertEqual(signature.name, signature._name.decode(encoding))
         self.assertEqual(signature.name.encode(encoding), signature._name)
 
+    def test_ascii(self):
+        self.assertRaises(
+                UnicodeEncodeError, Signature, 'Foo Ibáñez', 'foo@example.com')
+
     def test_latin1(self):
         encoding = 'iso-8859-1'
-        signature = Signature('Foo Ibáñez', 'foo@example.com', 1322174594, 60,
-                              encoding)
+        signature = Signature(
+            'Foo Ibáñez', 'foo@example.com', encoding=encoding)
         self.assertEqual(encoding, signature._encoding)
         self.assertEqual(signature.name, signature._name.decode(encoding))
         self.assertEqual(signature.name.encode(encoding), signature._name)
 
     def test_now(self):
-        self.assertRaises(TypeError, Signature, 'Foo Ibáñez',
-                          'foo@example.com', 1322174594)
-        signature = Signature('Foo Ibáñez', 'foo@example.com')
-        encoding = signature._encoding
-        self.assertEqual(encoding, 'utf-8')
+        encoding = 'utf-8'
+        signature = Signature(
+            'Foo Ibáñez', 'foo@example.com', encoding=encoding)
         self.assertEqual(encoding, signature._encoding)
         self.assertEqual(signature.name, signature._name.decode(encoding))
         self.assertEqual(signature.name.encode(encoding), signature._name)