diff --git a/tests/scripts/generate_psa_tests.py b/tests/scripts/generate_psa_tests.py
index 75ef353..adbf886 100755
--- a/tests/scripts/generate_psa_tests.py
+++ b/tests/scripts/generate_psa_tests.py
@@ -443,51 +443,41 @@
                 continue
             yield self.key_for_lifetime(lifetime)
 
-    def keys_for_usage_flags(
+    def key_for_usage_flags(
             self,
             usage_flags: List[str],
             short: Optional[str] = None,
-            test_implicit_usage: Optional[bool] = False
-    ) -> Iterator[StorageTestData]:
+            test_implicit_usage: Optional[bool] = True
+    ) -> StorageTestData:
         """Construct a test key for the given key usage."""
         usage = ' | '.join(usage_flags) if usage_flags else '0'
         if short is None:
             short = re.sub(r'\bPSA_KEY_USAGE_', r'', usage)
-        extra_desc = ' with implication' if test_implicit_usage else ''
+        extra_desc = ' without implication' if test_implicit_usage else ''
         description = 'usage' + extra_desc + ': ' + short
         key1 = StorageTestData(version=self.version,
                                id=1, lifetime=0x00000001,
                                type='PSA_KEY_TYPE_RAW_DATA', bits=8,
                                expected_usage=usage,
+                               without_implicit_usage=not test_implicit_usage,
                                usage=usage, alg=0, alg2=0,
                                material=b'K',
                                description=description)
-        yield key1
-
-        if test_implicit_usage:
-            description = 'usage without implication' + ': ' + short
-            key2 = StorageTestData(version=self.version,
-                                   id=1, lifetime=0x00000001,
-                                   type='PSA_KEY_TYPE_RAW_DATA', bits=8,
-                                   without_implicit_usage=True,
-                                   usage=usage, alg=0, alg2=0,
-                                   material=b'K',
-                                   description=description)
-            yield key2
+        return key1
 
     def generate_keys_for_usage_flags(self, **kwargs) -> Iterator[StorageTestData]:
         """Generate test keys covering usage flags."""
         known_flags = sorted(self.constructors.key_usage_flags)
-        yield from self.keys_for_usage_flags(['0'], **kwargs)
+        yield self.key_for_usage_flags(['0'], **kwargs)
         for usage_flag in known_flags:
-            yield from self.keys_for_usage_flags([usage_flag], **kwargs)
+            yield self.key_for_usage_flags([usage_flag], **kwargs)
         for flag1, flag2 in zip(known_flags,
                                 known_flags[1:] + [known_flags[0]]):
-            yield from self.keys_for_usage_flags([flag1, flag2], **kwargs)
+            yield self.key_for_usage_flags([flag1, flag2], **kwargs)
 
     def generate_key_for_all_usage_flags(self) -> Iterator[StorageTestData]:
         known_flags = sorted(self.constructors.key_usage_flags)
-        yield from self.keys_for_usage_flags(known_flags, short='all known')
+        yield self.key_for_usage_flags(known_flags, short='all known')
 
     def all_keys_for_usage_flags(self) -> Iterator[StorageTestData]:
         yield from self.generate_keys_for_usage_flags()
@@ -593,8 +583,8 @@
 
     def all_keys_for_usage_flags(self) -> Iterator[StorageTestData]:
         """Generate test keys covering usage flags."""
-        yield from self.generate_keys_for_usage_flags(test_implicit_usage=True)
-        yield from self.generate_key_for_all_usage_flags()
+        yield from super().all_keys_for_usage_flags()
+        yield from self.generate_keys_for_usage_flags(test_implicit_usage=False)
 
     def keys_for_implicit_usage(
             self,