diff --git a/PIL/ImageFile.py b/PIL/ImageFile.py
index adb27f2bd..5e4745d76 100644
--- a/PIL/ImageFile.py
+++ b/PIL/ImageFile.py
@@ -133,11 +133,27 @@ class ImageFile(Image.Image):
             return pixel
 
         self.map = None
-
+        use_mmap = self.filename and len(self.tile) == 1
+        # As of pypy 2.1.0, memory mapping was failing here.
+        use_mmap = use_mmap and not hasattr(sys, 'pypy_version_info') 
+        
         readonly = 0
 
-        if self.filename and len(self.tile) == 1 and not hasattr(sys, 'pypy_version_info'):
-            # As of pypy 2.1.0, memory mapping was failing here.
+        # look for read/seek overrides
+        try:
+            read = self.load_read
+            # don't use mmap if there are custom read/seek functions
+            use_mmap = False
+        except AttributeError:
+            read = self.fp.read
+
+        try:
+            seek = self.load_seek
+            use_mmap = False
+        except AttributeError:
+            seek = self.fp.seek
+
+        if use_mmap:
             # try memory mapping
             d, e, o, a = self.tile[0]
             if d == "raw" and a[0] == self.mode and a[0] in Image._MAPMODES:
@@ -165,19 +181,7 @@ class ImageFile(Image.Image):
 
         self.load_prepare()
 
-        # look for read/seek overrides
-        try:
-            read = self.load_read
-        except AttributeError:
-            read = self.fp.read
-
-        try:
-            seek = self.load_seek
-        except AttributeError:
-            seek = self.fp.seek
-
         if not self.map:
-
             # sort tiles in file order
             self.tile.sort(key=_tilesort)
 
diff --git a/Tests/test_file_xpm.py b/Tests/test_file_xpm.py
index 16a811a4c..4fc393808 100644
--- a/Tests/test_file_xpm.py
+++ b/Tests/test_file_xpm.py
@@ -1,4 +1,4 @@
-from helper import unittest, PillowTestCase
+from helper import unittest, PillowTestCase, lena
 
 from PIL import Image
 
@@ -15,6 +15,9 @@ class TestFileXpm(PillowTestCase):
         self.assertEqual(im.size, (128, 128))
         self.assertEqual(im.format, "XPM")
 
+        #large error due to quantization->44 colors.
+        self.assert_image_similar(im.convert('RGB'), lena('RGB'), 60) 
+
     def test_load_read(self):
         # Arrange
         im = Image.open(TEST_FILE)