diff --git a/Lib/test/support/__init__.py b/Lib/test/support/__init__.py
index b21978a..1ce3a78 100644
--- a/Lib/test/support/__init__.py
+++ b/Lib/test/support/__init__.py
@@ -36,6 +36,11 @@
 from .testresult import get_test_runner
 
 
+try:
+    from _testcapi import unicode_legacy_string
+except ImportError:
+    unicode_legacy_string = None
+
 __all__ = [
     # globals
     "PIPE_MAX_SIZE", "verbose", "max_memuse", "use_resources", "failfast",
@@ -426,6 +431,9 @@
         lzma = None
     return unittest.skipUnless(lzma, reason)
 
+requires_legacy_unicode_capi = unittest.skipUnless(unicode_legacy_string,
+                        'requires legacy Unicode C API')
+
 is_jython = sys.platform.startswith('java')
 
 is_android = hasattr(sys, 'getandroidapilevel')
diff --git a/Lib/test/test_csv.py b/Lib/test/test_csv.py
index d421be0..a92870c 100644
--- a/Lib/test/test_csv.py
+++ b/Lib/test/test_csv.py
@@ -250,9 +250,9 @@
             self.assertRaises(OSError, writer.writerows, BadIterable())
 
     @support.cpython_only
+    @support.requires_legacy_unicode_capi
     def test_writerows_legacy_strings(self):
         import _testcapi
-
         c = _testcapi.unicode_legacy_string('a')
         with TemporaryFile("w+", newline='') as fileobj:
             writer = csv.writer(fileobj)
diff --git a/Lib/test/test_decimal.py b/Lib/test/test_decimal.py
index 716e6eb..9dbae44 100644
--- a/Lib/test/test_decimal.py
+++ b/Lib/test/test_decimal.py
@@ -33,7 +33,8 @@
 import numbers
 import locale
 from test.support import (run_unittest, run_doctest, is_resource_enabled,
-                          requires_IEEE_754, requires_docstrings)
+                          requires_IEEE_754, requires_docstrings,
+                          requires_legacy_unicode_capi)
 from test.support import (TestFailed,
                           run_with_locale, cpython_only)
 from test.support.import_helper import import_fresh_module
@@ -582,6 +583,7 @@
             self.assertRaises(InvalidOperation, Decimal, "1_2_\u00003")
 
     @cpython_only
+    @requires_legacy_unicode_capi
     def test_from_legacy_strings(self):
         import _testcapi
         Decimal = self.decimal.Decimal
@@ -2817,6 +2819,7 @@
                                               Overflow])
 
     @cpython_only
+    @requires_legacy_unicode_capi
     def test_from_legacy_strings(self):
         import _testcapi
         c = self.decimal.Context()
diff --git a/Lib/test/test_getargs2.py b/Lib/test/test_getargs2.py
index d39ea56..0956019 100644
--- a/Lib/test/test_getargs2.py
+++ b/Lib/test/test_getargs2.py
@@ -976,6 +976,7 @@
         buf = bytearray()
         self.assertRaises(ValueError, getargs_et_hash, 'abc\xe9', 'latin1', buf)
 
+    @support.requires_legacy_unicode_capi
     def test_u(self):
         from _testcapi import getargs_u
         self.assertEqual(getargs_u('abc\xe9'), 'abc\xe9')
@@ -985,6 +986,7 @@
         self.assertRaises(TypeError, getargs_u, memoryview(b'memoryview'))
         self.assertRaises(TypeError, getargs_u, None)
 
+    @support.requires_legacy_unicode_capi
     def test_u_hash(self):
         from _testcapi import getargs_u_hash
         self.assertEqual(getargs_u_hash('abc\xe9'), 'abc\xe9')
@@ -994,6 +996,7 @@
         self.assertRaises(TypeError, getargs_u_hash, memoryview(b'memoryview'))
         self.assertRaises(TypeError, getargs_u_hash, None)
 
+    @support.requires_legacy_unicode_capi
     def test_Z(self):
         from _testcapi import getargs_Z
         self.assertEqual(getargs_Z('abc\xe9'), 'abc\xe9')
@@ -1003,6 +1006,7 @@
         self.assertRaises(TypeError, getargs_Z, memoryview(b'memoryview'))
         self.assertIsNone(getargs_Z(None))
 
+    @support.requires_legacy_unicode_capi
     def test_Z_hash(self):
         from _testcapi import getargs_Z_hash
         self.assertEqual(getargs_Z_hash('abc\xe9'), 'abc\xe9')
diff --git a/Lib/test/test_unicode.py b/Lib/test/test_unicode.py
index afc9555..d485bc7 100644
--- a/Lib/test/test_unicode.py
+++ b/Lib/test/test_unicode.py
@@ -723,6 +723,7 @@
         self.assertFalse("0".isidentifier())
 
     @support.cpython_only
+    @support.requires_legacy_unicode_capi
     def test_isidentifier_legacy(self):
         import _testcapi
         u = '𝖀𝖓𝖎𝖈𝖔𝖉𝖊'
@@ -2350,6 +2351,7 @@
         self.assertEqual(len(args), 1)
 
     @support.cpython_only
+    @support.requires_legacy_unicode_capi
     def test_resize(self):
         from _testcapi import getargs_u
         for length in range(1, 100, 7):
@@ -2920,6 +2922,7 @@
         self.assertRaises(SystemError, unicode_copycharacters, s, 0, b'', 0, 0)
 
     @support.cpython_only
+    @support.requires_legacy_unicode_capi
     def test_encode_decimal(self):
         from _testcapi import unicode_encodedecimal
         self.assertEqual(unicode_encodedecimal('123'),
@@ -2936,6 +2939,7 @@
             unicode_encodedecimal, "123\u20ac", "replace")
 
     @support.cpython_only
+    @support.requires_legacy_unicode_capi
     def test_transform_decimal(self):
         from _testcapi import unicode_transformdecimaltoascii as transform_decimal
         self.assertEqual(transform_decimal('123'),