diff --git a/scripts/mbedtls_dev/bignum_common.py b/scripts/mbedtls_dev/bignum_common.py
index b22846b..7d7170d 100644
--- a/scripts/mbedtls_dev/bignum_common.py
+++ b/scripts/mbedtls_dev/bignum_common.py
@@ -209,12 +209,12 @@
         if cls.arity not in cls.arities:
             raise ValueError("Unsupported number of operands!")
         if cls.input_style == "arch_split":
-            test_objects = (cls(a_value, b_value, bits_in_limb=bil)
-                            for a_value, b_value in cls.get_value_pairs()
+            test_objects = (cls(a, b, bits_in_limb=bil)
+                            for a, b in cls.get_value_pairs()
                             for bil in cls.limb_sizes)
         else:
-            test_objects = (cls(a_value, b_value) for
-                            a_value, b_value in cls.get_value_pairs())
+            test_objects = (cls(a, b)
+                            for a, b in cls.get_value_pairs())
         yield from (valid_test_object.create_test_case()
                     for valid_test_object in filter(
                         lambda test_object: test_object.is_valid,
@@ -225,6 +225,7 @@
 class ModOperationCommon(OperationCommon):
     #pylint: disable=abstract-method
     """Target for bignum mod_raw test case generation."""
+    moduli = [] # type: List[str]
 
     def __init__(self, val_n: str, val_a: str, val_b: str = "0",
                  bits_in_limb: int = 64) -> None:
@@ -258,6 +259,34 @@
     def r2(self) -> int: # pylint: disable=invalid-name
         return pow(self.r, 2)
 
+    @property
+    def is_valid(self) -> bool:
+        if self.int_a >= self.int_n:
+            return False
+        if self.arity == 2 and self.int_b >= self.int_n:
+            return False
+        return True
+
+    @classmethod
+    def generate_function_tests(cls) -> Iterator[test_case.TestCase]:
+        if cls.input_style not in cls.input_styles:
+            raise ValueError("Unknown input style!")
+        if cls.arity not in cls.arities:
+            raise ValueError("Unsupported number of operands!")
+        if cls.input_style == "arch_split":
+            test_objects = (cls(n, a, b, bits_in_limb=bil)
+                            for n in cls.moduli
+                            for a, b in cls.get_value_pairs()
+                            for bil in cls.limb_sizes)
+        else:
+            test_objects = (cls(n, a, b)
+                            for n in cls.moduli
+                            for a, b in cls.get_value_pairs())
+        yield from (valid_test_object.create_test_case()
+                    for valid_test_object in filter(
+                        lambda test_object: test_object.is_valid,
+                        test_objects
+                        ))
 
 # BEGIN MERGE SLOT 1