diff --git a/PIL/ImageFile.py b/PIL/ImageFile.py
index cda64efcf..a66452478 100644
--- a/PIL/ImageFile.py
+++ b/PIL/ImageFile.py
@@ -170,6 +170,9 @@ class ImageFile(Image.Image):
                             self.map, self.size, d, e, o, a
                             )
                     readonly = 1
+                    # After trashing self.im, we might need to reload the palette data.
+                    if self.palette:
+                        self.palette.dirty = 1
                 except (AttributeError, EnvironmentError, ImportError):
                     self.map = None
 
diff --git a/Tests/images/multipage-mmap.tiff b/Tests/images/multipage-mmap.tiff
new file mode 100644
index 000000000..162b0521b
Binary files /dev/null and b/Tests/images/multipage-mmap.tiff differ
diff --git a/Tests/test_imagesequence.py b/Tests/test_imagesequence.py
index 8c65e6358..0877bfb8a 100644
--- a/Tests/test_imagesequence.py
+++ b/Tests/test_imagesequence.py
@@ -63,5 +63,14 @@ class TestImageSequence(PillowTestCase):
             self.assert_image_equal(frame, firstFrame)
             break
 
+
+    def test_palette_mmap(self):
+        # Using mmap in ImageFile can require to reload the palette.
+        im = Image.open('Tests/images/multipage-mmap.tiff')
+        color1 = im.getpalette()[0:3]
+        im.seek(0)
+        color2 = im.getpalette()[0:3]
+        self.assertEqual(color1, color2)
+
 if __name__ == '__main__':
     unittest.main()