diff --git a/Tests/test_numpy.py b/Tests/test_numpy.py
index f4f88ff41..988189391 100644
--- a/Tests/test_numpy.py
+++ b/Tests/test_numpy.py
@@ -56,7 +56,8 @@ def test_numpy_to_image():
     assert_image(to_image(numpy.uint8, 4), "RGBA", (10, 10))
 
 
-# based on an erring example at http://is.gd/6F0esS
+# based on an erring example at http://is.gd/6F0esS  (which resolves to)
+# http://stackoverflow.com/questions/10854903/what-is-causing-dimension-dependent-attributeerror-in-pil-fromarray-function
 def test_3d_array():
     a = numpy.ones((10, 10, 10), dtype=numpy.uint8)
     assert_image(Image.fromarray(a[1, :, :]), "L", (10, 10))