diff --git a/PIL/ImageWin.py b/PIL/ImageWin.py
index aa90b887b..300d118c9 100644
--- a/PIL/ImageWin.py
+++ b/PIL/ImageWin.py
@@ -23,23 +23,26 @@ from PIL import Image
 
 class HDC:
     """
-    Wraps a HDC integer. The resulting object can be passed to the
+    Wraps an HDC integer. The resulting object can be passed to the
     :py:meth:`~PIL.ImageWin.Dib.draw` and :py:meth:`~PIL.ImageWin.Dib.expose`
     methods.
     """
     def __init__(self, dc):
         self.dc = dc
+
     def __int__(self):
         return self.dc
 
+
 class HWND:
     """
-    Wraps a HWND integer. The resulting object can be passed to the
+    Wraps an HWND integer. The resulting object can be passed to the
     :py:meth:`~PIL.ImageWin.Dib.draw` and :py:meth:`~PIL.ImageWin.Dib.expose`
     methods, instead of a DC.
     """
     def __init__(self, wnd):
         self.wnd = wnd
+
     def __int__(self):
         return self.wnd
 
@@ -79,13 +82,12 @@ class Dib:
         if image:
             self.paste(image)
 
-
     def expose(self, handle):
         """
         Copy the bitmap contents to a device context.
 
-        :param handle: Device context (HDC), cast to a Python integer, or a HDC
-                       or HWND instance.  In PythonWin, you can use the
+        :param handle: Device context (HDC), cast to a Python integer, or an
+                       HDC or HWND instance.  In PythonWin, you can use the
                        :py:meth:`CDC.GetHandleAttrib` to get a suitable handle.
         """
         if isinstance(handle, HWND):
@@ -109,7 +111,7 @@ class Dib:
         necessary.
         """
         if not src:
-            src = (0,0) + self.size
+            src = (0, 0) + self.size
         if isinstance(handle, HWND):
             dc = self.image.getdc(handle)
             try:
@@ -120,7 +122,6 @@ class Dib:
             result = self.image.draw(handle, dst, src)
         return result
 
-
     def query_palette(self, handle):
         """
         Installs the palette associated with the image in the given device
@@ -146,7 +147,6 @@ class Dib:
             result = self.image.query_palette(handle)
         return result
 
-
     def paste(self, im, box=None):
         """
         Paste a PIL image into the bitmap image.
@@ -166,7 +166,6 @@ class Dib:
         else:
             self.image.paste(im.im)
 
-
     def frombytes(self, buffer):
         """
         Load display memory contents from byte data.
@@ -176,7 +175,6 @@ class Dib:
         """
         return self.image.frombytes(buffer)
 
-
     def tobytes(self):
         """
         Copy display memory contents to bytes object.
@@ -204,6 +202,7 @@ class Dib:
         )
         return self.tobytes()
 
+
 ##
 # Create a Window with the given title size.
 
@@ -235,6 +234,7 @@ class Window:
     def mainloop(self):
         Image.core.eventloop()
 
+
 ##
 # Create an image window which displays the given image.
 
diff --git a/Tests/test_imagewin.py b/Tests/test_imagewin.py
index 69dbdbe82..6fb58a0dc 100644
--- a/Tests/test_imagewin.py
+++ b/Tests/test_imagewin.py
@@ -1,16 +1,123 @@
-from helper import unittest, PillowTestCase, lena
+from helper import unittest, PillowTestCase, hopper
 
-from PIL import Image
 from PIL import ImageWin
+import sys
 
 
 class TestImageWin(PillowTestCase):
 
     def test_sanity(self):
-        dir(Image)
         dir(ImageWin)
         pass
 
+    def test_hdc(self):
+        # Arrange
+        dc = 50
+
+        # Act
+        hdc = ImageWin.HDC(dc)
+        dc2 = int(hdc)
+
+        # Assert
+        self.assertEqual(dc2, 50)
+
+    def test_hwnd(self):
+        # Arrange
+        wnd = 50
+
+        # Act
+        hwnd = ImageWin.HWND(wnd)
+        wnd2 = int(hwnd)
+
+        # Assert
+        self.assertEqual(wnd2, 50)
+
+
+@unittest.skipUnless(sys.platform.startswith('win32'), "Windows only")
+class TestImageWinDib(PillowTestCase):
+
+    def test_dib_image(self):
+        # Arrange
+        im = hopper()
+
+        # Act
+        dib = ImageWin.Dib(im)
+
+        # Assert
+        self.assertEqual(dib.size, im.size)
+
+    def test_dib_mode_string(self):
+        # Arrange
+        mode = "RGBA"
+        size = (128, 128)
+
+        # Act
+        dib = ImageWin.Dib(mode, size)
+
+        # Assert
+        self.assertEqual(dib.size, (128, 128))
+
+    def test_dib_paste(self):
+        # Arrange
+        im = hopper()
+
+        mode = "RGBA"
+        size = (128, 128)
+        dib = ImageWin.Dib(mode, size)
+
+        # Act
+        dib.paste(im)
+
+        # Assert
+        self.assertEqual(dib.size, (128, 128))
+
+    def test_dib_paste_bbox(self):
+        # Arrange
+        im = hopper()
+        bbox = (0, 0, 10, 10)
+
+        mode = "RGBA"
+        size = (128, 128)
+        dib = ImageWin.Dib(mode, size)
+
+        # Act
+        dib.paste(im, bbox)
+
+        # Assert
+        self.assertEqual(dib.size, (128, 128))
+
+    def test_dib_frombytes_tobytes_roundtrip(self):
+        # Arrange
+        # Make two different DIB images
+        im = hopper()
+        dib1 = ImageWin.Dib(im)
+
+        mode = "RGB"
+        size = (128, 128)
+        dib2 = ImageWin.Dib(mode, size)
+
+        # Confirm they're different
+        self.assertNotEqual(dib1.tobytes(), dib2.tobytes())
+
+        # Act
+        # Make one the same as the using tobytes()/frombytes()
+        buffer = dib1.tobytes()
+        dib2.frombytes(buffer)
+
+        # Assert
+        # Confirm they're the same
+        self.assertEqual(dib1.tobytes(), dib2.tobytes())
+
+    def test_dib_fromstring_tostring_deprecated(self):
+        # Arrange
+        im = hopper()
+        dib = ImageWin.Dib(im)
+        buffer = dib.tobytes()
+
+        # Act/Assert
+        self.assert_warning(DeprecationWarning, lambda: dib.tostring())
+        self.assert_warning(DeprecationWarning, lambda: dib.fromstring(buffer))
+
 
 if __name__ == '__main__':
     unittest.main()