diff --git a/Tests/test_file_jpeg.py b/Tests/test_file_jpeg.py
index b68be4503..ddcc6d0cc 100644
--- a/Tests/test_file_jpeg.py
+++ b/Tests/test_file_jpeg.py
@@ -586,6 +586,10 @@ class TestFileJpeg(PillowTestCase):
         im.draft(im.mode, (100, 100))
         self.assertEqual(im.size, (100, 100))
 
+        im = Image.open("Tests/images/flower2.jpg")
+        im.thumbnail((100, 75))
+        self.assertEqual(im.size, (100, 75))
+
 
 @unittest.skipUnless(sys.platform.startswith('win32'), "Windows only")
 class TestFileCloseW32(PillowTestCase):
diff --git a/src/PIL/Image.py b/src/PIL/Image.py
index 5c1b2a2a7..e4c6cc7cc 100644
--- a/src/PIL/Image.py
+++ b/src/PIL/Image.py
@@ -2129,11 +2129,12 @@ class Image(object):
 
         self.draft(None, size)
 
-        im = self.resize(size, resample)
+        if self.size != size:
+            im = self.resize(size, resample)
 
-        self.im = im.im
-        self.mode = im.mode
-        self._size = size
+            self.im = im.im
+            self._size = size
+        self.mode = self.im.mode
 
         self.readonly = 0
         self.pyaccess = None