diff --git a/scripts/generate_psa_tests.py b/scripts/generate_psa_tests.py
index c6c068e2a..caf239477 100755
--- a/scripts/generate_psa_tests.py
+++ b/scripts/generate_psa_tests.py
@@ -341,23 +341,27 @@ class OpFail:
     def test_cases_for_algorithm(
             self,
             alg: crypto_knowledge.Algorithm,
+            categories: Iterable[crypto_knowledge.AlgorithmCategory]
     ) -> Iterator[test_case.TestCase]:
         """Generate operation failure test cases for the specified algorithm."""
-        for category in crypto_knowledge.AlgorithmCategory:
-            if category == crypto_knowledge.AlgorithmCategory.PAKE:
-                # PAKE operations are not implemented yet
-                pass
-            elif category.requires_key():
+        for category in categories:
+            if category.requires_key():
                 yield from self.one_key_test_cases(alg, category)
             else:
                 yield from self.no_key_test_cases(alg, category)
 
     def all_test_cases(self) -> Iterator[test_case.TestCase]:
         """Generate all test cases for operations that must fail."""
-        algorithms = sorted(self.constructors.algorithms)
-        for expr in self.constructors.generate_expressions(algorithms):
-            alg = crypto_knowledge.Algorithm(expr)
-            yield from self.test_cases_for_algorithm(alg)
+        algorithm_constructors = sorted(self.constructors.algorithms)
+        algorithms = [crypto_knowledge.Algorithm(alg)
+                      for alg in self.constructors.generate_expressions(
+                          algorithm_constructors)]
+        categories = [
+            cat for cat in crypto_knowledge.AlgorithmCategory
+            if cat != crypto_knowledge.AlgorithmCategory.PAKE # not implemented yet
+        ]
+        for alg in algorithms:
+            yield from self.test_cases_for_algorithm(alg, categories)
 
 
 class StorageKey(psa_storage.Key):