diff --git a/README.rst b/README.rst
index a9679a5c3..fd988ad65 100644
--- a/README.rst
+++ b/README.rst
@@ -80,6 +80,21 @@ Current platform support for Pillow. Binary distributions are contributed for ea
 .. [1] x86 only
 .. [2] In some cases, x86 support may indicate 32-bit compilation on 64-bit architecture (vs. compilation on 32-bit hardware).
 
+Donations
+---------
+
+You can help fund Pillow development!
+
+.. Note:: New contributors: please add your name (and donation preference) here and send a pull request.
+
+Pillow is a volunteer effort led by Alex Clark. Any contributor interested in receiving donations may add their name (and donation preference) here.
+
++--------------------------------------+---------------------------------------+
+| **Developer**                        | **Preference**                        |
++--------------------------------------+---------------------------------------+
+| Alex Clark (fork author)             | http://gittip.com/aclark4life         |
++--------------------------------------+---------------------------------------+
+
 Python Imaging Library
 ======================
 
@@ -386,4 +401,3 @@ Python Imaging Library
         http://mingw.org (compiler)
         http://sebsauvage.net/python/mingw.html (build instructions)
         http://sourceforge.net/projects/gnuwin32 (prebuilt libraries)
-
diff --git a/Tests/test_file_webp.py b/Tests/test_file_webp.py
index f7aad97f9..5d48f0aff 100644
--- a/Tests/test_file_webp.py
+++ b/Tests/test_file_webp.py
@@ -2,10 +2,10 @@ from tester import *
 
 from PIL import Image
 
-codecs = dir(Image.core)
-		
-if "webp_encoder" not in codecs or "webp_decoder" not in codecs:
-	    skip("webp support not available")
+try:
+    import _webp
+except:
+    skip('webp support not installed')
 		
 def test_read():
     """ Can we write a webp without error. Does it have the bits we expect?"""
diff --git a/libImaging/AlphaComposite.c b/libImaging/AlphaComposite.c
index 93afe2a95..9433fae53 100644
--- a/libImaging/AlphaComposite.c
+++ b/libImaging/AlphaComposite.c
@@ -69,21 +69,22 @@ ImagingAlphaComposite(Imaging imDst, Imaging imSrc)
                 // almost equivalent to:
                 // tmp = a + (2 << (n-1)), ((tmp >> n) + tmp) >> n
 
+                UINT32 tmpr, tmpg, tmpb;
                 UINT16 blend = dst->a * (255 - src->a);
                 UINT16 outa255 = src->a * 255 + blend;
                 // There we use 7 bits for precision.
                 // We could use more, but we go beyond 32 bits.
                 UINT16 coef1 = src->a * 255 * 255 * 128 / outa255;
-                UINT16 coef2 = blend * 255 * 128 / outa255;
+                UINT16 coef2 = 255 * 128 - coef1;
 
                 #define SHIFTFORDIV255(a)\
-                    ((a >> 8) + a >> 8)
+                    ((((a) >> 8) + a) >> 8)
 
-                UINT32 tmpr = src->r * coef1 + dst->r * coef2 + (0x80 << 7);
+                tmpr = src->r * coef1 + dst->r * coef2 + (0x80 << 7);
                 out->r = SHIFTFORDIV255(tmpr) >> 7;
-                UINT32 tmpg = src->g * coef1 + dst->g * coef2 + (0x80 << 7);
+                tmpg = src->g * coef1 + dst->g * coef2 + (0x80 << 7);
                 out->g = SHIFTFORDIV255(tmpg) >> 7;
-                UINT32 tmpb = src->b * coef1 + dst->b * coef2 + (0x80 << 7);
+                tmpb = src->b * coef1 + dst->b * coef2 + (0x80 << 7);
                 out->b = SHIFTFORDIV255(tmpb) >> 7;
                 out->a = SHIFTFORDIV255(outa255 + 0x80);
             }