diff --git a/Lib/packaging/tests/test_command_bdist_dumb.py b/Lib/packaging/tests/test_command_bdist_dumb.py
index ce1563f..41b0dd0 100644
--- a/Lib/packaging/tests/test_command_bdist_dumb.py
+++ b/Lib/packaging/tests/test_command_bdist_dumb.py
@@ -3,16 +3,10 @@
 import sys
 import os
 
-# zlib is not used here, but if it's not available
-# test_simple_built will fail
-try:
-    import zlib
-except ImportError:
-    zlib = None
-
 from packaging.dist import Distribution
 from packaging.command.bdist_dumb import bdist_dumb
 from packaging.tests import unittest, support
+from packaging.tests.support import requires_zlib
 
 
 SETUP_PY = """\
@@ -39,7 +33,7 @@
         sys.argv[:] = self.old_sys_argv[1]
         super(BuildDumbTestCase, self).tearDown()
 
-    @unittest.skipUnless(zlib, "requires zlib")
+    @requires_zlib
     def test_simple_built(self):
 
         # let's create a simple package
diff --git a/Lib/test/test_shutil.py b/Lib/test/test_shutil.py
index 475a26b..839f742 100644
--- a/Lib/test/test_shutil.py
+++ b/Lib/test/test_shutil.py
@@ -21,7 +21,7 @@
 import warnings
 
 from test import support
-from test.support import TESTFN, check_warnings, captured_stdout
+from test.support import TESTFN, check_warnings, captured_stdout, requires_zlib
 
 try:
     import bz2
@@ -39,11 +39,6 @@
     UID_GID_SUPPORT = False
 
 try:
-    import zlib
-except ImportError:
-    zlib = None
-
-try:
     import zipfile
     ZIP_SUPPORT = True
 except ImportError:
@@ -444,7 +439,7 @@
             self.assertEqual(getattr(file1_stat, 'st_flags'),
                              getattr(file2_stat, 'st_flags'))
 
-    @unittest.skipUnless(zlib, "requires zlib")
+    @requires_zlib
     def test_make_tarball(self):
         # creating something to tar
         tmpdir = self.mkdtemp()
@@ -507,7 +502,7 @@
         base_name = os.path.join(tmpdir2, 'archive')
         return tmpdir, tmpdir2, base_name
 
-    @unittest.skipUnless(zlib, "Requires zlib")
+    @requires_zlib
     @unittest.skipUnless(find_executable('tar') and find_executable('gzip'),
                          'Need the tar command to run')
     def test_tarfile_vs_tar(self):
@@ -562,7 +557,7 @@
         tarball = base_name + '.tar'
         self.assertTrue(os.path.exists(tarball))
 
-    @unittest.skipUnless(zlib, "Requires zlib")
+    @requires_zlib
     @unittest.skipUnless(ZIP_SUPPORT, 'Need zip support to run')
     def test_make_zipfile(self):
         # creating something to tar
@@ -586,7 +581,7 @@
         base_name = os.path.join(tmpdir, 'archive')
         self.assertRaises(ValueError, make_archive, base_name, 'xxx')
 
-    @unittest.skipUnless(zlib, "Requires zlib")
+    @requires_zlib
     def test_make_archive_owner_group(self):
         # testing make_archive with owner and group, with various combinations
         # this works even if there's not gid/uid support
@@ -614,7 +609,7 @@
         self.assertTrue(os.path.exists(res))
 
 
-    @unittest.skipUnless(zlib, "Requires zlib")
+    @requires_zlib
     @unittest.skipUnless(UID_GID_SUPPORT, "Requires grp and pwd support")
     def test_tarfile_root_owner(self):
         tmpdir, tmpdir2, base_name =  self._create_files()
@@ -683,7 +678,7 @@
                     diff.append(file_)
         return diff
 
-    @unittest.skipUnless(zlib, "Requires zlib")
+    @requires_zlib
     def test_unpack_archive(self):
         formats = ['tar', 'gztar', 'zip']
         if BZ2_SUPPORTED:
diff --git a/Lib/test/test_zipfile.py b/Lib/test/test_zipfile.py
index 90aab86..9663715 100644
--- a/Lib/test/test_zipfile.py
+++ b/Lib/test/test_zipfile.py
@@ -1,9 +1,3 @@
-# We can test part of the module without zlib.
-try:
-    import zlib
-except ImportError:
-    zlib = None
-
 import io
 import os
 import sys
@@ -19,7 +13,7 @@
 from random import randint, random
 from unittest import skipUnless
 
-from test.support import TESTFN, run_unittest, findfile, unlink
+from test.support import TESTFN, run_unittest, findfile, unlink, requires_zlib
 
 TESTFN2 = TESTFN + "2"
 TESTFNDIR = TESTFN + "d"
@@ -269,44 +263,44 @@
         for f in (TESTFN2, TemporaryFile(), io.BytesIO()):
             self.zip_iterlines_test(f, zipfile.ZIP_STORED)
 
-    @skipUnless(zlib, "requires zlib")
+    @requires_zlib
     def test_deflated(self):
         for f in (TESTFN2, TemporaryFile(), io.BytesIO()):
             self.zip_test(f, zipfile.ZIP_DEFLATED)
 
 
-    @skipUnless(zlib, "requires zlib")
+    @requires_zlib
     def test_open_deflated(self):
         for f in (TESTFN2, TemporaryFile(), io.BytesIO()):
             self.zip_open_test(f, zipfile.ZIP_DEFLATED)
 
-    @skipUnless(zlib, "requires zlib")
+    @requires_zlib
     def test_random_open_deflated(self):
         for f in (TESTFN2, TemporaryFile(), io.BytesIO()):
             self.zip_random_open_test(f, zipfile.ZIP_DEFLATED)
 
-    @skipUnless(zlib, "requires zlib")
+    @requires_zlib
     def test_readline_read_deflated(self):
         # Issue #7610: calls to readline() interleaved with calls to read().
         for f in (TESTFN2, TemporaryFile(), io.BytesIO()):
             self.zip_readline_read_test(f, zipfile.ZIP_DEFLATED)
 
-    @skipUnless(zlib, "requires zlib")
+    @requires_zlib
     def test_readline_deflated(self):
         for f in (TESTFN2, TemporaryFile(), io.BytesIO()):
             self.zip_readline_test(f, zipfile.ZIP_DEFLATED)
 
-    @skipUnless(zlib, "requires zlib")
+    @requires_zlib
     def test_readlines_deflated(self):
         for f in (TESTFN2, TemporaryFile(), io.BytesIO()):
             self.zip_readlines_test(f, zipfile.ZIP_DEFLATED)
 
-    @skipUnless(zlib, "requires zlib")
+    @requires_zlib
     def test_iterlines_deflated(self):
         for f in (TESTFN2, TemporaryFile(), io.BytesIO()):
             self.zip_iterlines_test(f, zipfile.ZIP_DEFLATED)
 
-    @skipUnless(zlib, "requires zlib")
+    @requires_zlib
     def test_low_compression(self):
         """Check for cases where compressed data is larger than original."""
         # Create the ZIP archive
@@ -359,7 +353,7 @@
             with open(TESTFN, "rb") as f:
                 self.assertEqual(zipfp.read(TESTFN), f.read())
 
-    @skipUnless(zlib, "requires zlib")
+    @requires_zlib
     def test_per_file_compression(self):
         """Check that files within a Zip archive can have different
         compression options."""
@@ -428,19 +422,18 @@
         # remove the test file subdirectories
         shutil.rmtree(os.path.join(os.getcwd(), 'ziptest2dir'))
 
-    def test_writestr_compression(self):
+    def test_writestr_compression_stored(self):
         zipfp = zipfile.ZipFile(TESTFN2, "w")
         zipfp.writestr("a.txt", "hello world", compress_type=zipfile.ZIP_STORED)
-        if zlib:
-            zipfp.writestr("b.txt", "hello world", compress_type=zipfile.ZIP_DEFLATED)
-
         info = zipfp.getinfo('a.txt')
         self.assertEqual(info.compress_type, zipfile.ZIP_STORED)
 
-        if zlib:
-            info = zipfp.getinfo('b.txt')
-            self.assertEqual(info.compress_type, zipfile.ZIP_DEFLATED)
-
+    @requires_zlib
+    def test_writestr_compression_deflated(self):
+        zipfp = zipfile.ZipFile(TESTFN2, "w")
+        zipfp.writestr("b.txt", "hello world", compress_type=zipfile.ZIP_DEFLATED)
+        info = zipfp.getinfo('b.txt')
+        self.assertEqual(info.compress_type, zipfile.ZIP_DEFLATED)
 
     def zip_test_writestr_permissions(self, f, compression):
         # Make sure that writestr creates files with mode 0600,
@@ -489,7 +482,7 @@
         except zipfile.BadZipFile:
             self.assertTrue(zipfp2.fp is None, 'zipfp is not closed')
 
-    @skipUnless(zlib, "requires zlib")
+    @requires_zlib
     def test_unicode_filenames(self):
         # bug #10801
         fname = findfile('zip_cp437_header.zip')
@@ -598,7 +591,7 @@
         for f in (TESTFN2, TemporaryFile(), io.BytesIO()):
             self.zip_test(f, zipfile.ZIP_STORED)
 
-    @skipUnless(zlib, "requires zlib")
+    @requires_zlib
     def test_deflated(self):
         for f in (TESTFN2, TemporaryFile(), io.BytesIO()):
             self.zip_test(f, zipfile.ZIP_DEFLATED)
@@ -958,7 +951,7 @@
     def test_testzip_with_bad_crc_stored(self):
         self.check_testzip_with_bad_crc(zipfile.ZIP_STORED)
 
-    @skipUnless(zlib, "requires zlib")
+    @requires_zlib
     def test_testzip_with_bad_crc_deflated(self):
         self.check_testzip_with_bad_crc(zipfile.ZIP_DEFLATED)
 
@@ -986,7 +979,7 @@
     def test_read_with_bad_crc_stored(self):
         self.check_read_with_bad_crc(zipfile.ZIP_STORED)
 
-    @skipUnless(zlib, "requires zlib")
+    @requires_zlib
     def test_read_with_bad_crc_deflated(self):
         self.check_read_with_bad_crc(zipfile.ZIP_DEFLATED)
 
@@ -1006,7 +999,7 @@
     def test_read_return_size_stored(self):
         self.check_read_return_size(zipfile.ZIP_STORED)
 
-    @skipUnless(zlib, "requires zlib")
+    @requires_zlib
     def test_read_return_size_deflated(self):
         self.check_read_return_size(zipfile.ZIP_DEFLATED)
 
@@ -1092,7 +1085,7 @@
         self.zip2.setpassword(b"perl")
         self.assertRaises(RuntimeError, self.zip2.read, "zero")
 
-    @skipUnless(zlib, "requires zlib")
+    @requires_zlib
     def test_good_password(self):
         self.zip.setpassword(b"python")
         self.assertEqual(self.zip.read("test.txt"), self.plain)
@@ -1142,7 +1135,7 @@
         for f in (TESTFN2, TemporaryFile(), io.BytesIO()):
             self.zip_test(f, zipfile.ZIP_STORED)
 
-    @skipUnless(zlib, "requires zlib")
+    @requires_zlib
     def test_deflated(self):
         for f in (TESTFN2, TemporaryFile(), io.BytesIO()):
             self.zip_test(f, zipfile.ZIP_DEFLATED)
@@ -1182,7 +1175,7 @@
         for f in (TESTFN2, TemporaryFile(), io.BytesIO()):
             self.zip_open_test(f, zipfile.ZIP_STORED)
 
-    @skipUnless(zlib, "requires zlib")
+    @requires_zlib
     def test_open_deflated(self):
         for f in (TESTFN2, TemporaryFile(), io.BytesIO()):
             self.zip_open_test(f, zipfile.ZIP_DEFLATED)
@@ -1210,13 +1203,13 @@
         for f in (TESTFN2, TemporaryFile(), io.BytesIO()):
             self.zip_random_open_test(f, zipfile.ZIP_STORED)
 
-    @skipUnless(zlib, "requires zlib")
+    @requires_zlib
     def test_random_open_deflated(self):
         for f in (TESTFN2, TemporaryFile(), io.BytesIO()):
             self.zip_random_open_test(f, zipfile.ZIP_DEFLATED)
 
 
-@skipUnless(zlib, "requires zlib")
+@requires_zlib
 class TestsWithMultipleOpens(unittest.TestCase):
     def setUp(self):
         # Create the ZIP archive
@@ -1408,28 +1401,28 @@
         for f in (TESTFN2, TemporaryFile(), io.BytesIO()):
             self.iterlines_test(f, zipfile.ZIP_STORED)
 
-    @skipUnless(zlib, "requires zlib")
+    @requires_zlib
     def test_read_deflated(self):
         for f in (TESTFN2, TemporaryFile(), io.BytesIO()):
             self.read_test(f, zipfile.ZIP_DEFLATED)
 
-    @skipUnless(zlib, "requires zlib")
+    @requires_zlib
     def test_readline_read_deflated(self):
         # Issue #7610: calls to readline() interleaved with calls to read().
         for f in (TESTFN2, TemporaryFile(), io.BytesIO()):
             self.readline_read_test(f, zipfile.ZIP_DEFLATED)
 
-    @skipUnless(zlib, "requires zlib")
+    @requires_zlib
     def test_readline_deflated(self):
         for f in (TESTFN2, TemporaryFile(), io.BytesIO()):
             self.readline_test(f, zipfile.ZIP_DEFLATED)
 
-    @skipUnless(zlib, "requires zlib")
+    @requires_zlib
     def test_readlines_deflated(self):
         for f in (TESTFN2, TemporaryFile(), io.BytesIO()):
             self.readlines_test(f, zipfile.ZIP_DEFLATED)
 
-    @skipUnless(zlib, "requires zlib")
+    @requires_zlib
     def test_iterlines_deflated(self):
         for f in (TESTFN2, TemporaryFile(), io.BytesIO()):
             self.iterlines_test(f, zipfile.ZIP_DEFLATED)
diff --git a/Lib/test/test_zipfile64.py b/Lib/test/test_zipfile64.py
index 0e7d73f..a8fb7ab 100644
--- a/Lib/test/test_zipfile64.py
+++ b/Lib/test/test_zipfile64.py
@@ -11,12 +11,6 @@
         'test requires loads of disk-space bytes and a long time to run'
     )
 
-# We can test part of the module without zlib.
-try:
-    import zlib
-except ImportError:
-    zlib = None
-
 import zipfile, os, unittest
 import time
 import sys
@@ -24,7 +18,7 @@
 from io import StringIO
 from tempfile import TemporaryFile
 
-from test.support import TESTFN, run_unittest
+from test.support import TESTFN, run_unittest, requires_zlib
 
 TESTFN2 = TESTFN + "2"
 
@@ -81,12 +75,12 @@
         for f in TemporaryFile(), TESTFN2:
             self.zipTest(f, zipfile.ZIP_STORED)
 
-    if zlib:
-        def testDeflated(self):
-            # Try the temp file first.  If we do TESTFN2 first, then it hogs
-            # gigabytes of disk space for the duration of the test.
-            for f in TemporaryFile(), TESTFN2:
-                self.zipTest(f, zipfile.ZIP_DEFLATED)
+    @requires_zlib
+    def testDeflated(self):
+        # Try the temp file first.  If we do TESTFN2 first, then it hogs
+        # gigabytes of disk space for the duration of the test.
+        for f in TemporaryFile(), TESTFN2:
+            self.zipTest(f, zipfile.ZIP_DEFLATED)
 
     def tearDown(self):
         for fname in TESTFN, TESTFN2:
diff --git a/Lib/test/test_zipimport.py b/Lib/test/test_zipimport.py
index 090f0f3..5aab6b4 100644
--- a/Lib/test/test_zipimport.py
+++ b/Lib/test/test_zipimport.py
@@ -9,12 +9,6 @@
 from test import support
 from test.test_importhooks import ImportHooksBaseTestCase, test_src, test_co
 
-# some tests can be ran even without zlib
-try:
-    import zlib
-except ImportError:
-    zlib = None
-
 from zipfile import ZipFile, ZipInfo, ZIP_STORED, ZIP_DEFLATED
 
 import zipimport
@@ -397,7 +391,7 @@
             os.remove(filename)
 
 
-@unittest.skipUnless(zlib, "requires zlib")
+@support.requires_zlib
 class CompressedZipImportTestCase(UncompressedZipImportTestCase):
     compression = ZIP_DEFLATED