diff --git a/scripts/mbedtls_dev/bignum_common.py b/scripts/mbedtls_dev/bignum_common.py
index 8b11bc2..ba30be4 100644
--- a/scripts/mbedtls_dev/bignum_common.py
+++ b/scripts/mbedtls_dev/bignum_common.py
@@ -17,6 +17,8 @@
 from abc import abstractmethod
 from typing import Iterator, List, Tuple, TypeVar
 
+from . import test_data_generation
+
 T = TypeVar('T') #pylint: disable=invalid-name
 
 def invmod(a: int, n: int) -> int:
@@ -63,8 +65,7 @@
     """Return all pair combinations from input values."""
     return [(x, y) for x in values for y in values]
 
-
-class OperationCommon:
+class OperationCommon(test_data_generation.BaseTest):
     """Common features for bignum binary operations.
 
     This adds functionality common in binary operation tests.
diff --git a/scripts/mbedtls_dev/bignum_core.py b/scripts/mbedtls_dev/bignum_core.py
index 0cc86b8..db9d1b7 100644
--- a/scripts/mbedtls_dev/bignum_core.py
+++ b/scripts/mbedtls_dev/bignum_core.py
@@ -16,20 +16,19 @@
 
 import random
 
-from abc import ABCMeta
 from typing import Dict, Iterator, List, Tuple
 
 from . import test_case
 from . import test_data_generation
 from . import bignum_common
 
-class BignumCoreTarget(test_data_generation.BaseTarget, metaclass=ABCMeta):
-    #pylint: disable=abstract-method
+class BignumCoreTarget(test_data_generation.BaseTarget):
+    #pylint: disable=abstract-method, too-few-public-methods
     """Target for bignum core test case generation."""
     target_basename = 'test_suite_bignum_core.generated'
 
 
-class BignumCoreShiftR(BignumCoreTarget, metaclass=ABCMeta):
+class BignumCoreShiftR(BignumCoreTarget, test_data_generation.BaseTest):
     """Test cases for mbedtls_bignum_core_shift_r()."""
     count = 0
     test_function = "mpi_core_shift_r"
@@ -69,7 +68,7 @@
             for count in counts:
                 yield cls(input_hex, descr, count).create_test_case()
 
-class BignumCoreCTLookup(BignumCoreTarget, metaclass=ABCMeta):
+class BignumCoreCTLookup(BignumCoreTarget, test_data_generation.BaseTest):
     """Test cases for mbedtls_mpi_core_ct_uint_table_lookup()."""
     test_function = "mpi_core_ct_uint_table_lookup"
     test_name = "Constant time MPI table lookup"
@@ -107,7 +106,8 @@
                 yield (cls(bitsize, bitsize_description, window_size)
                        .create_test_case())
 
-class BignumCoreOperation(bignum_common.OperationCommon, BignumCoreTarget, metaclass=ABCMeta):
+class BignumCoreOperation(BignumCoreTarget, bignum_common.OperationCommon,
+                          metaclass=ABCMeta):
     #pylint: disable=abstract-method
     """Common features for bignum core operations."""
     input_values = [
@@ -297,7 +297,7 @@
                 yield cur_op.create_test_case()
 
 
-class BignumCoreMontmul(BignumCoreTarget):
+class BignumCoreMontmul(BignumCoreTarget, test_data_generation.BaseTest):
     """Test cases for Montgomery multiplication."""
     count = 0
     test_function = "mpi_core_montmul"
diff --git a/scripts/mbedtls_dev/bignum_mod.py b/scripts/mbedtls_dev/bignum_mod.py
index 2bd7fbb..a604cc0 100644
--- a/scripts/mbedtls_dev/bignum_mod.py
+++ b/scripts/mbedtls_dev/bignum_mod.py
@@ -14,12 +14,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from abc import ABCMeta
-
 from . import test_data_generation
 
-class BignumModTarget(test_data_generation.BaseTarget, metaclass=ABCMeta):
-    #pylint: disable=abstract-method
+class BignumModTarget(test_data_generation.BaseTarget):
+    #pylint: disable=abstract-method, too-few-public-methods
     """Target for bignum mod test case generation."""
     target_basename = 'test_suite_bignum_mod.generated'
 
diff --git a/scripts/mbedtls_dev/bignum_mod_raw.py b/scripts/mbedtls_dev/bignum_mod_raw.py
index bd694a6..4f12d9a 100644
--- a/scripts/mbedtls_dev/bignum_mod_raw.py
+++ b/scripts/mbedtls_dev/bignum_mod_raw.py
@@ -21,8 +21,8 @@
 from . import test_data_generation
 from . import bignum_common
 
-class BignumModRawTarget(test_data_generation.BaseTarget, metaclass=ABCMeta):
-    #pylint: disable=abstract-method
+class BignumModRawTarget(test_data_generation.BaseTarget):
+    #pylint: disable=abstract-method, too-few-public-methods
     """Target for bignum mod_raw test case generation."""
     target_basename = 'test_suite_bignum_mod_raw.generated'
 
diff --git a/scripts/mbedtls_dev/test_data_generation.py b/scripts/mbedtls_dev/test_data_generation.py
index eec0f9d..3d703ee 100644
--- a/scripts/mbedtls_dev/test_data_generation.py
+++ b/scripts/mbedtls_dev/test_data_generation.py
@@ -25,6 +25,7 @@
 import os
 import posixpath
 import re
+import inspect
 
 from abc import ABCMeta, abstractmethod
 from typing import Callable, Dict, Iterable, Iterator, List, Type, TypeVar
@@ -35,12 +36,8 @@
 T = TypeVar('T') #pylint: disable=invalid-name
 
 
-class BaseTarget(metaclass=ABCMeta):
-    """Base target for test case generation.
-
-    Child classes of this class represent an output file, and can be referred
-    to as file targets. These indicate where test cases will be written to for
-    all subclasses of the file target, which is set by `target_basename`.
+class BaseTest(metaclass=ABCMeta):
+    """Base class for test case generation.
 
     Attributes:
         count: Counter for test cases from this class.
@@ -48,8 +45,6 @@
             automatically generated using the class, or manually set.
         dependencies: A list of dependencies required for the test case.
         show_test_count: Toggle for inclusion of `count` in the test description.
-        target_basename: Basename of file to write generated tests to. This
-            should be specified in a child class of BaseTarget.
         test_function: Test function which the class generates cases for.
         test_name: A common name or description of the test function. This can
             be `test_function`, a clearer equivalent, or a short summary of the
@@ -59,7 +54,6 @@
     case_description = ""
     dependencies = [] # type: List[str]
     show_test_count = True
-    target_basename = ""
     test_function = ""
     test_name = ""
 
@@ -121,6 +115,20 @@
         """
         raise NotImplementedError
 
+
+class BaseTarget:
+    """Base target for test case generation.
+
+    Child classes of this class represent an output file, and can be referred
+    to as file targets. These indicate where test cases will be written to for
+    all subclasses of the file target, which is set by `target_basename`.
+
+    Attributes:
+        target_basename: Basename of file to write generated tests to. This
+            should be specified in a child class of BaseTarget.
+    """
+    target_basename = ""
+
     @classmethod
     def generate_tests(cls) -> Iterator[test_case.TestCase]:
         """Generate test cases for the class and its subclasses.
@@ -132,7 +140,7 @@
         yield from `generate_tests()` in each. Calling this method on a class X
         will yield test cases from all classes derived from X.
         """
-        if cls.test_function:
+        if issubclass(cls, BaseTest) and not inspect.isabstract(cls):
             yield from cls.generate_function_tests()
         for subclass in sorted(cls.__subclasses__(), key=lambda c: c.__name__):
             yield from subclass.generate_tests()