diff --git a/Tests/test_lib_pack.py b/Tests/test_lib_pack.py
index b23ae58af..b4c8b6a56 100644
--- a/Tests/test_lib_pack.py
+++ b/Tests/test_lib_pack.py
@@ -123,10 +123,10 @@ class TestLibPack(PillowTestCase):
         self.assert_pack("YCbCr", "YCbCr", 3, (1,2,3), (4,5,6), (7,8,9))
         self.assert_pack("YCbCr", "YCbCr;L", 3, (1,4,7), (2,5,8), (3,6,9))
         self.assert_pack("YCbCr", "YCbCrX",
-            '\x01\x02\x03\xff\x05\x06\x07\xff\t\n\x0b\xff',
+            b'\x01\x02\x03\xff\x05\x06\x07\xff\t\n\x0b\xff',
             (1,2,3), (5,6,7), (9,10,11))
         self.assert_pack("YCbCr", "YCbCrK",
-            '\x01\x02\x03\xff\x05\x06\x07\xff\t\n\x0b\xff',
+            b'\x01\x02\x03\xff\x05\x06\x07\xff\t\n\x0b\xff',
             (1,2,3), (5,6,7), (9,10,11))
         self.assert_pack("YCbCr", "Y", 1, (1,0,8,9), (2,0,8,9), (3,0,8,0))
         self.assert_pack("YCbCr", "Cb", 1, (6,1,8,9), (6,2,8,9), (6,3,8,9))
diff --git a/Tests/test_mode_i16.py b/Tests/test_mode_i16.py
index d51847199..53bbce572 100644
--- a/Tests/test_mode_i16.py
+++ b/Tests/test_mode_i16.py
@@ -87,12 +87,10 @@ class TestModeI16(PillowTestCase):
         def tobytes(mode):
             return Image.new(mode, (1, 1), 1).tobytes()
 
-        order = 1 if Image._ENDIAN == '<' else -1
-
         self.assertEqual(tobytes("L"), b"\x01")
         self.assertEqual(tobytes("I;16"), b"\x01\x00")
         self.assertEqual(tobytes("I;16B"), b"\x00\x01")
-        self.assertEqual(tobytes("I"), b"\x01\x00\x00\x00"[::order])
+        self.assertEqual(tobytes("I"), b"\x01\x00\x00\x00")
 
     def test_convert(self):