diff --git a/tests/scripts/generate_psa_tests.py b/tests/scripts/generate_psa_tests.py
index ca94d7d..d25af22 100755
--- a/tests/scripts/generate_psa_tests.py
+++ b/tests/scripts/generate_psa_tests.py
@@ -206,7 +206,7 @@
                 continue
                 # For public key we expect that key generation fails with
                 # INVALID_ARGUMENT. It is handled by KeyGenerate class.
-            if not kt.name.endswith('_PUBLIC_KEY'):
+            if not kt.is_public():
                 yield test_case_for_key_type_not_supported(
                     'generate', kt.expression, bits,
                     finish_family_dependencies(generate_dependencies, bits),
@@ -822,8 +822,10 @@
                 for key_type in sorted(alg_with_keys[alg]):
                     # The key types must be filtered to fit the specific usage flag.
                     kt = crypto_knowledge.KeyType(key_type)
-                    if kt.is_valid_for_signature(usage):
-                        yield self.keys_for_implicit_usage(usage, alg, kt)
+                    if kt.is_public() and '_SIGN_' in usage:
+                        # Can't sign with a public key
+                        continue
+                    yield self.keys_for_implicit_usage(usage, alg, kt)
 
     def generate_all_keys(self) -> Iterator[StorageTestData]:
         yield from super().generate_all_keys()