diff --git a/Tests/check_imaging_leaks.py b/Tests/check_imaging_leaks.py
index 2b9a9605b..a109b5cd5 100755
--- a/Tests/check_imaging_leaks.py
+++ b/Tests/check_imaging_leaks.py
@@ -2,17 +2,15 @@
 
 from __future__ import division
 
-import sys
-
 from PIL import Image
 
-from .helper import PillowTestCase, unittest
+from .helper import PillowTestCase, is_win32, unittest
 
 min_iterations = 100
 max_iterations = 10000
 
 
-@unittest.skipIf(sys.platform.startswith("win32"), "requires Unix or macOS")
+@unittest.skipIf(is_win32(), "requires Unix or macOS")
 class TestImagingLeaks(PillowTestCase):
     def _get_mem_usage(self):
         from resource import getpagesize, getrusage, RUSAGE_SELF
diff --git a/Tests/check_j2k_leaks.py b/Tests/check_j2k_leaks.py
index 4614529ed..d9c6c68b7 100755
--- a/Tests/check_j2k_leaks.py
+++ b/Tests/check_j2k_leaks.py
@@ -1,9 +1,8 @@
-import sys
 from io import BytesIO
 
 from PIL import Image
 
-from .helper import PillowTestCase, unittest
+from .helper import PillowTestCase, is_win32, unittest
 
 # Limits for testing the leak
 mem_limit = 1024 * 1048576
@@ -13,7 +12,7 @@ codecs = dir(Image.core)
 test_file = "Tests/images/rgb_trns_ycbc.jp2"
 
 
-@unittest.skipIf(sys.platform.startswith("win32"), "requires Unix or macOS")
+@unittest.skipIf(is_win32(), "requires Unix or macOS")
 class TestJpegLeaks(PillowTestCase):
     def setUp(self):
         if "jpeg2k_encoder" not in codecs or "jpeg2k_decoder" not in codecs:
diff --git a/Tests/check_jpeg_leaks.py b/Tests/check_jpeg_leaks.py
index 2f758ba10..8cb93f2dd 100644
--- a/Tests/check_jpeg_leaks.py
+++ b/Tests/check_jpeg_leaks.py
@@ -1,7 +1,6 @@
-import sys
 from io import BytesIO
 
-from .helper import PillowTestCase, hopper, unittest
+from .helper import PillowTestCase, hopper, is_win32, unittest
 
 iterations = 5000
 
@@ -15,7 +14,7 @@ valgrind --tool=massif python test-installed.py -s -v Tests/check_jpeg_leaks.py
 """
 
 
-@unittest.skipIf(sys.platform.startswith("win32"), "requires Unix or macOS")
+@unittest.skipIf(is_win32(), "requires Unix or macOS")
 class TestJpegLeaks(PillowTestCase):
 
     """
diff --git a/Tests/helper.py b/Tests/helper.py
index c352f54b9..312c6aa4e 100644
--- a/Tests/helper.py
+++ b/Tests/helper.py
@@ -368,6 +368,14 @@ def on_ci():
     )
 
 
+def is_win32():
+    return sys.platform.startswith("win32")
+
+
+def is_pypy():
+    return hasattr(sys, "pypy_translation_info")
+
+
 if sys.platform == "win32":
     IMCONVERT = os.environ.get("MAGICK_HOME", "")
     if IMCONVERT:
diff --git a/Tests/test_core_resources.py b/Tests/test_core_resources.py
index eefb1a0ef..0aedb91c9 100644
--- a/Tests/test_core_resources.py
+++ b/Tests/test_core_resources.py
@@ -4,9 +4,7 @@ import sys
 
 from PIL import Image
 
-from .helper import PillowTestCase, unittest
-
-is_pypy = hasattr(sys, "pypy_version_info")
+from .helper import PillowTestCase, is_pypy, unittest
 
 
 class TestCoreStats(PillowTestCase):
@@ -87,7 +85,7 @@ class TestCoreMemory(PillowTestCase):
         stats = Image.core.get_stats()
         self.assertGreaterEqual(stats["new_count"], 1)
         self.assertGreaterEqual(stats["allocated_blocks"], 64)
-        if not is_pypy:
+        if not is_pypy():
             self.assertGreaterEqual(stats["freed_blocks"], 64)
 
     def test_get_blocks_max(self):
@@ -108,7 +106,7 @@ class TestCoreMemory(PillowTestCase):
         if sys.maxsize < 2 ** 32:
             self.assertRaises(ValueError, Image.core.set_blocks_max, 2 ** 29)
 
-    @unittest.skipIf(is_pypy, "images are not collected")
+    @unittest.skipIf(is_pypy(), "images are not collected")
     def test_set_blocks_max_stats(self):
         Image.core.reset_stats()
         Image.core.set_blocks_max(128)
@@ -123,7 +121,7 @@ class TestCoreMemory(PillowTestCase):
         self.assertEqual(stats["freed_blocks"], 0)
         self.assertEqual(stats["blocks_cached"], 64)
 
-    @unittest.skipIf(is_pypy, "images are not collected")
+    @unittest.skipIf(is_pypy(), "images are not collected")
     def test_clear_cache_stats(self):
         Image.core.reset_stats()
         Image.core.clear_cache()
@@ -153,7 +151,7 @@ class TestCoreMemory(PillowTestCase):
         self.assertGreaterEqual(stats["allocated_blocks"], 16)
         self.assertGreaterEqual(stats["reused_blocks"], 0)
         self.assertEqual(stats["blocks_cached"], 0)
-        if not is_pypy:
+        if not is_pypy():
             self.assertGreaterEqual(stats["freed_blocks"], 16)
 
 
diff --git a/Tests/test_file_jpeg.py b/Tests/test_file_jpeg.py
index 7f9bf7c1d..5a34a3faa 100644
--- a/Tests/test_file_jpeg.py
+++ b/Tests/test_file_jpeg.py
@@ -1,10 +1,16 @@
 import os
-import sys
 from io import BytesIO
 
 from PIL import Image, ImageFile, JpegImagePlugin
 
-from .helper import PillowTestCase, cjpeg_available, djpeg_available, hopper, unittest
+from .helper import (
+    PillowTestCase,
+    cjpeg_available,
+    djpeg_available,
+    hopper,
+    is_win32,
+    unittest,
+)
 
 codecs = dir(Image.core)
 
@@ -654,7 +660,7 @@ class TestFileJpeg(PillowTestCase):
         self.assertNotIn("photoshop", im.info)
 
 
-@unittest.skipUnless(sys.platform.startswith("win32"), "Windows only")
+@unittest.skipUnless(is_win32(), "Windows only")
 class TestFileCloseW32(PillowTestCase):
     def setUp(self):
         if "jpeg_encoder" not in codecs or "jpeg_decoder" not in codecs:
diff --git a/Tests/test_file_png.py b/Tests/test_file_png.py
index 6d76a6caa..07e84ef72 100644
--- a/Tests/test_file_png.py
+++ b/Tests/test_file_png.py
@@ -1,11 +1,10 @@
-import sys
 import zlib
 from io import BytesIO
 
 from PIL import Image, ImageFile, PngImagePlugin
 from PIL._util import py3
 
-from .helper import PillowLeakTestCase, PillowTestCase, hopper, unittest
+from .helper import PillowLeakTestCase, PillowTestCase, hopper, is_win32, unittest
 
 try:
     from PIL import _webp
@@ -650,7 +649,7 @@ class TestFilePng(PillowTestCase):
         self.assert_image_similar(im, expected, 0.23)
 
 
-@unittest.skipIf(sys.platform.startswith("win32"), "requires Unix or macOS")
+@unittest.skipIf(is_win32(), "requires Unix or macOS")
 class TestTruncatedPngPLeaks(PillowLeakTestCase):
     mem_limit = 2 * 1024  # max increase in K
     iterations = 100  # Leak is 56k/iteration, this will leak 5.6megs
diff --git a/Tests/test_file_tiff.py b/Tests/test_file_tiff.py
index c3f55150c..c8a4c2df3 100644
--- a/Tests/test_file_tiff.py
+++ b/Tests/test_file_tiff.py
@@ -1,12 +1,11 @@
 import logging
-import sys
 from io import BytesIO
 
 from PIL import Image, TiffImagePlugin, features
 from PIL._util import py3
 from PIL.TiffImagePlugin import RESOLUTION_UNIT, X_RESOLUTION, Y_RESOLUTION
 
-from .helper import PillowTestCase, hopper, unittest
+from .helper import PillowTestCase, hopper, is_win32, unittest
 
 logger = logging.getLogger(__name__)
 
@@ -612,7 +611,7 @@ class TestFileTiff(PillowTestCase):
             im.load()
 
 
-@unittest.skipUnless(sys.platform.startswith("win32"), "Windows only")
+@unittest.skipUnless(is_win32(), "Windows only")
 class TestFileTiffW32(PillowTestCase):
     def test_fd_leak(self):
         tmpfile = self.tempfile("temp.tif")
diff --git a/Tests/test_font_leaks.py b/Tests/test_font_leaks.py
index 14b368585..9b5fe2055 100644
--- a/Tests/test_font_leaks.py
+++ b/Tests/test_font_leaks.py
@@ -1,13 +1,11 @@
 from __future__ import division
 
-import sys
-
 from PIL import Image, ImageDraw, ImageFont, features
 
-from .helper import PillowLeakTestCase, unittest
+from .helper import PillowLeakTestCase, is_win32, unittest
 
 
-@unittest.skipIf(sys.platform.startswith("win32"), "requires Unix or macOS")
+@unittest.skipIf(is_win32(), "requires Unix or macOS")
 class TestTTypeFontLeak(PillowLeakTestCase):
     # fails at iteration 3 in master
     iterations = 10
diff --git a/Tests/test_image.py b/Tests/test_image.py
index 493b4735a..cbf52b3b4 100644
--- a/Tests/test_image.py
+++ b/Tests/test_image.py
@@ -1,11 +1,10 @@
 import os
 import shutil
-import sys
 
 from PIL import Image
 from PIL._util import py3
 
-from .helper import PillowTestCase, hopper, unittest
+from .helper import PillowTestCase, hopper, is_win32, unittest
 
 
 class TestImage(PillowTestCase):
@@ -150,9 +149,7 @@ class TestImage(PillowTestCase):
         im.paste(0, (0, 0, 100, 100))
         self.assertFalse(im.readonly)
 
-    @unittest.skipIf(
-        sys.platform.startswith("win32"), "Test requires opening tempfile twice"
-    )
+    @unittest.skipIf(is_win32(), "Test requires opening tempfile twice")
     def test_readonly_save(self):
         temp_file = self.tempfile("temp.bmp")
         shutil.copy("Tests/images/rgb32bf-rgba.bmp", temp_file)
diff --git a/Tests/test_image_access.py b/Tests/test_image_access.py
index b69c2040f..577df3dff 100644
--- a/Tests/test_image_access.py
+++ b/Tests/test_image_access.py
@@ -3,7 +3,7 @@ import sys
 
 from PIL import Image
 
-from .helper import PillowTestCase, hopper, on_ci, unittest
+from .helper import PillowTestCase, hopper, is_win32, on_ci, unittest
 
 # CFFI imports pycparser which doesn't support PYTHONOPTIMIZE=2
 # https://github.com/eliben/pycparser/pull/198#issuecomment-317001670
@@ -333,7 +333,7 @@ class TestCffi(AccessTest):
 
 class TestEmbeddable(unittest.TestCase):
     @unittest.skipIf(
-        not sys.platform.startswith("win32") or on_ci(),
+        not is_win32() or on_ci(),
         "Failing on AppVeyor / GitHub Actions when run from subprocess, not from shell",
     )
     def test_embeddable(self):
diff --git a/Tests/test_imagefont.py b/Tests/test_imagefont.py
index 6a2d572a9..6944404c1 100644
--- a/Tests/test_imagefont.py
+++ b/Tests/test_imagefont.py
@@ -9,7 +9,7 @@ from io import BytesIO
 
 from PIL import Image, ImageDraw, ImageFont, features
 
-from .helper import PillowTestCase, unittest
+from .helper import PillowTestCase, is_pypy, is_win32, unittest
 
 FONT_PATH = "Tests/fonts/FreeMono.ttf"
 FONT_SIZE = 20
@@ -464,10 +464,7 @@ class TestImageFont(PillowTestCase):
         with self.assertRaises(UnicodeEncodeError):
             font.getsize(u"’")
 
-    @unittest.skipIf(
-        sys.version.startswith("2") or hasattr(sys, "pypy_translation_info"),
-        "requires CPython 3.3+",
-    )
+    @unittest.skipIf(sys.version.startswith("2") or is_pypy(), "requires CPython 3.3+")
     def test_unicode_extended(self):
         # issue #3777
         text = u"A\u278A\U0001F12B"
@@ -504,7 +501,7 @@ class TestImageFont(PillowTestCase):
                 name = font.getname()
                 self.assertEqual(("FreeMono", "Regular"), name)
 
-    @unittest.skipIf(sys.platform.startswith("win32"), "requires Unix or macOS")
+    @unittest.skipIf(is_win32(), "requires Unix or macOS")
     def test_find_linux_font(self):
         # A lot of mocking here - this is more for hitting code and
         # catching syntax like errors
@@ -550,7 +547,7 @@ class TestImageFont(PillowTestCase):
                         font_directory + "/Duplicate.ttf", "Duplicate"
                     )
 
-    @unittest.skipIf(sys.platform.startswith("win32"), "requires Unix or macOS")
+    @unittest.skipIf(is_win32(), "requires Unix or macOS")
     def test_find_macos_font(self):
         # Like the linux test, more cover hitting code rather than testing
         # correctness.
diff --git a/Tests/test_imageshow.py b/Tests/test_imageshow.py
index 1c756da9f..aac48d6c0 100644
--- a/Tests/test_imageshow.py
+++ b/Tests/test_imageshow.py
@@ -1,8 +1,6 @@
-import sys
-
 from PIL import Image, ImageShow
 
-from .helper import PillowTestCase, hopper, on_ci, on_github_actions, unittest
+from .helper import PillowTestCase, hopper, is_win32, on_ci, on_github_actions, unittest
 
 
 class TestImageShow(PillowTestCase):
@@ -37,7 +35,7 @@ class TestImageShow(PillowTestCase):
         ImageShow._viewers.pop(0)
 
     @unittest.skipUnless(
-        on_ci() and not (sys.platform == "win32" and on_github_actions()),
+        on_ci() and not (is_win32() and on_github_actions()),
         "Only run on CIs; hangs on Windows on GitHub Actions",
     )
     def test_show(self):
diff --git a/Tests/test_imagewin.py b/Tests/test_imagewin.py
index 92fcdc28d..2b2034187 100644
--- a/Tests/test_imagewin.py
+++ b/Tests/test_imagewin.py
@@ -1,8 +1,6 @@
-import sys
-
 from PIL import ImageWin
 
-from .helper import PillowTestCase, hopper, unittest
+from .helper import PillowTestCase, hopper, is_win32, unittest
 
 
 class TestImageWin(PillowTestCase):
@@ -32,7 +30,7 @@ class TestImageWin(PillowTestCase):
         self.assertEqual(wnd2, 50)
 
 
-@unittest.skipUnless(sys.platform.startswith("win32"), "Windows only")
+@unittest.skipUnless(is_win32(), "Windows only")
 class TestImageWinDib(PillowTestCase):
     def test_dib_image(self):
         # Arrange
diff --git a/Tests/test_imagewin_pointers.py b/Tests/test_imagewin_pointers.py
index efa3753b9..d7c22a209 100644
--- a/Tests/test_imagewin_pointers.py
+++ b/Tests/test_imagewin_pointers.py
@@ -1,14 +1,13 @@
 import ctypes
-import sys
 from io import BytesIO
 
 from PIL import Image, ImageWin
 
-from .helper import PillowTestCase, hopper
+from .helper import PillowTestCase, hopper, is_win32
 
 # see https://github.com/python-pillow/Pillow/pull/1431#issuecomment-144692652
 
-if sys.platform.startswith("win32"):
+if is_win32():
     import ctypes.wintypes
 
     class BITMAPFILEHEADER(ctypes.Structure):
diff --git a/Tests/test_main.py b/Tests/test_main.py
index 936a938f9..c6f9a694e 100644
--- a/Tests/test_main.py
+++ b/Tests/test_main.py
@@ -5,14 +5,12 @@ import subprocess
 import sys
 from unittest import TestCase
 
-from .helper import on_github_actions, unittest
+from .helper import is_pypy, is_win32, on_github_actions, unittest
 
 
 class TestMain(TestCase):
     @unittest.skipIf(
-        sys.platform == "win32"
-        and hasattr(sys, "pypy_translation_info")
-        and on_github_actions(),
+        is_win32() and is_pypy() and on_github_actions(),
         "Failing on Windows on GitHub Actions running PyPy",
     )
     def test_main(self):
diff --git a/Tests/test_map.py b/Tests/test_map.py
index 3fc42651b..8d4e32219 100644
--- a/Tests/test_map.py
+++ b/Tests/test_map.py
@@ -2,7 +2,7 @@ import sys
 
 from PIL import Image
 
-from .helper import PillowTestCase, unittest
+from .helper import PillowTestCase, is_win32, unittest
 
 try:
     import numpy
@@ -10,7 +10,7 @@ except ImportError:
     numpy = None
 
 
-@unittest.skipIf(sys.platform.startswith("win32"), "Win32 does not call map_buffer")
+@unittest.skipIf(is_win32(), "Win32 does not call map_buffer")
 class TestMap(PillowTestCase):
     def test_overflow(self):
         # There is the potential to overflow comparisons in map.c
diff --git a/Tests/test_shell_injection.py b/Tests/test_shell_injection.py
index 35a3dcfcd..97774a0a4 100644
--- a/Tests/test_shell_injection.py
+++ b/Tests/test_shell_injection.py
@@ -1,5 +1,4 @@
 import shutil
-import sys
 
 from PIL import GifImagePlugin, Image, JpegImagePlugin
 
@@ -7,6 +6,7 @@ from .helper import (
     PillowTestCase,
     cjpeg_available,
     djpeg_available,
+    is_win32,
     netpbm_available,
     unittest,
 )
@@ -17,7 +17,7 @@ TEST_GIF = "Tests/images/hopper.gif"
 test_filenames = ("temp_';", 'temp_";', "temp_'\"|", "temp_'\"||", "temp_'\"&&")
 
 
-@unittest.skipIf(sys.platform.startswith("win32"), "requires Unix or macOS")
+@unittest.skipIf(is_win32(), "requires Unix or macOS")
 class TestShellInjection(PillowTestCase):
     def assert_save_filename_check(self, src_img, save_func):
         for filename in test_filenames: