diff --git a/pysstv/tests/test_color.py b/pysstv/tests/test_color.py
index 4f50dc7..97003f1 100644
--- a/pysstv/tests/test_color.py
+++ b/pysstv/tests/test_color.py
@@ -17,12 +17,14 @@ class TestMartinM1(unittest.TestCase):
         self.lena = color.MartinM1(lena, 48000, 16)
 
     def test_gen_freq_bits(self):
-        expected = pickle.load(open(get_asset_filename("MartinM1_freq_bits.p")))
+        with open(get_asset_filename("MartinM1_freq_bits.p"), 'rb') as f:
+            expected = pickle.load(f)
         actual = list(islice(self.s.gen_freq_bits(), 0, 1000))
         self.assertEqual(expected, actual)
 
     def test_gen_freq_bits_lena(self):
-        expected = pickle.load(open(get_asset_filename("MartinM1_freq_bits_lena.p")))
+        with open(get_asset_filename("MartinM1_freq_bits_lena.p"), 'rb') as f:
+            expected = pickle.load(f)
         actual = list(islice(self.lena.gen_freq_bits(), 0, 1000))
         self.assertEqual(expected, actual)
 
@@ -40,7 +42,7 @@ class TestMartinM1(unittest.TestCase):
         self.maxDiff = None
         line_numbers = [1, 10, 100]
         for line in line_numbers:
-            file = open(get_asset_filename("MartinM1_encode_line_lena%d.p" % line))
-            expected = pickle.load(file)
+            with open(get_asset_filename("MartinM1_encode_line_lena%d.p" % line), 'rb') as f:
+                expected = pickle.load(f)
             actual = list(self.lena.encode_line(line))
             self.assertEqual(expected, actual)
diff --git a/pysstv/tests/test_sstv.py b/pysstv/tests/test_sstv.py
index ffcd630..1b7ac39 100644
--- a/pysstv/tests/test_sstv.py
+++ b/pysstv/tests/test_sstv.py
@@ -1,5 +1,6 @@
 import unittest
-from itertools import islice, izip
+from itertools import islice
+from six.moves import zip
 import pickle
 import mock
 from mock import MagicMock
@@ -46,7 +47,7 @@ class TestSSTV(unittest.TestCase):
     def test_gen_values(self):
         gen_values = self.s.gen_values()
         expected = pickle.load(open(get_asset_filename("SSTV_gen_values.p")))
-        for e, g in izip(expected, gen_values):
+        for e, g in zip(expected, gen_values):
             self.assertAlmostEqual(e, g, delta=0.000000001)
 
     def test_gen_samples(self):
@@ -59,7 +60,7 @@ class TestSSTV(unittest.TestCase):
         sstv.random = MagicMock(return_value=0.4)  # xkcd:221
         expected = pickle.load(open(get_asset_filename("SSTV_gen_samples.p")))
         actual = list(islice(gen_values, 0, 1000))
-        for e, a in izip(expected, actual):
+        for e, a in zip(expected, actual):
             self.assertAlmostEqual(e, a, delta=1)
 
     def test_write_wav(self):