diff --git a/test/helper.py b/test/helper.py
index 8c45858b6..0958c56a9 100644
--- a/test/helper.py
+++ b/test/helper.py
@@ -129,22 +129,21 @@ py3 = (sys.version_info >= (3, 0))
 #         success()
 #     else:
 #         failure(msg or "got %r, doesn't match pattern %r" % (v, pattern))
-#
-#
-# # helpers
-#
-# from io import BytesIO
-#
-#
-# def fromstring(data):
-#     from PIL import Image
-#     return Image.open(BytesIO(data))
-#
-#
-# def tostring(im, format, **options):
-#     out = BytesIO()
-#     im.save(out, format, **options)
-#     return out.getvalue()
+
+
+# helpers
+
+def fromstring(data):
+    from io import BytesIO
+    from PIL import Image
+    return Image.open(BytesIO(data))
+
+
+def tostring(im, format, **options):
+    from io import BytesIO
+    out = BytesIO()
+    im.save(out, format, **options)
+    return out.getvalue()
 
 
 def lena(mode="RGB", cache={}):
diff --git a/test/test_image_tobitmap.py b/test/test_image_tobitmap.py
index 00e5af0cd..4e2a16df0 100644
--- a/test/test_image_tobitmap.py
+++ b/test/test_image_tobitmap.py
@@ -1,21 +1,19 @@
-from helper import unittest, PillowTestCase, lena
-
-from PIL import Image
+from helper import unittest, PillowTestCase, lena, fromstring
 
 
 class TestImage(PillowTestCase):
 
-def test_sanity(self):
+    def test_sanity(self):
 
-    self.assertRaises(ValueError, lambda: lena().tobitmap())
-    assert_no_exception(lambda: lena().convert("1").tobitmap())
+        self.assertRaises(ValueError, lambda: lena().tobitmap())
+        lena().convert("1").tobitmap()
 
-    im1 = lena().convert("1")
+        im1 = lena().convert("1")
 
-    bitmap = im1.tobitmap()
+        bitmap = im1.tobitmap()
 
-    assert_true(isinstance(bitmap, bytes))
-    assert_image_equal(im1, fromstring(bitmap))
+        self.assertIsInstance(bitmap, bytes)
+        self.assert_image_equal(im1, fromstring(bitmap))
 
 
 if __name__ == '__main__':