diff --git a/scripts/mbedtls_dev/bignum_mod_raw.py b/scripts/mbedtls_dev/bignum_mod_raw.py
index 60f2feded6..5d4bda2a7d 100644
--- a/scripts/mbedtls_dev/bignum_mod_raw.py
+++ b/scripts/mbedtls_dev/bignum_mod_raw.py
@@ -30,6 +30,96 @@ class BignumModRawTarget(test_data_generation.BaseTarget):
 
 # BEGIN MERGE SLOT 2
 
+class BignumModRawSub(BignumModRawOperation):
+    """Test cases for bignum mod raw sub."""
+    count = 0
+    symbol = "-"
+    test_function = "mpi_mod_raw_sub"
+    test_name = "mbedtls_mpi_mod_raw_sub"
+    unique_combinations_only = False
+
+    input_values = [
+        "0", "1", "fe", "ff", "fffe", "ffff",
+        "fffffffffffffffe", "ffffffffffffffff",
+        "fffffffffffffffffffffffffffffffe",
+        "ffffffffffffffffffffffffffffffff",
+        "1234567890abcdef01234567890abcdef0",
+        "3653f8dd9b1f282e4067c3584ee207f8da94e3e8ab73738f",
+        "fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffe",
+        "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff",
+        "1234567890abcdef01234567890abcdef01234567890abcdef01234567890abcdef0",
+        (
+            "14c15c910b11ad28cc21ce88d0060cc54278c2614e1bcb383bb4a570294c4ea3"
+            "738d243a6e58d5ca49c7b59b995253fd6c79a3de69f85e3131f3b9238224b122"
+            "c3e4a892d9196ada4fcfa583e1df8af9b474c7e89286a1754abcb06ae8abb93f"
+            "01d89a024cdce7a6d7288ff68c320f89f1347e0cdd905ecfd160c5d0ef412ed6"
+        )
+    ]
+
+    modulus_values = [
+        "7", "ff",
+        "d1c127a667786703830500038ebaef20e5a3e2dc378fb75b"
+        "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff43",
+        "fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff67",
+        (
+            "c93ba7ec74d96f411ba008bdb78e63ff11bb5df46a51e16b2c9d156f8e4e18ab"
+            "f5e052cb01f47d0d1925a77f60991577e128fb6f52f34a27950a594baadd3d80"
+            "57abeb222cf3cca962db16abf79f2ada5bd29ab2f51244bf295eff9f6aaba130"
+            "2efc449b128be75eeaca04bc3c1a155d11d14e8be32a2c8287b3996cf6ad5223"
+        ),
+        (
+            "5c083126e978d4fdf3b645a1cac083126e978d4fdf3b645a1cac083126e978d4"
+            "fdf3b645a1cac083126e978d4fdf3b645a1cac083126e978d4fdf3b645a1cac0"
+            "83126e978d4fdf3b645a1cac083126e978d4fdf3b645a1cac083126e978d4fdf"
+            "3b645a1cac083126e978d4fdf3b645a1cac083126e978d4fdf3b645a1cac05d2"
+        )
+    ]
+
+    descr_tpl = '{} #{} \"{}\" - \"{}\" % \"{}\".'
+
+    BITS_IN_LIMB = 32
+
+    @property
+    def boundary(self) -> int:
+        return self.int_n
+
+    @property
+    def x(self): # pylint: disable=invalid-name
+        return (self.int_a - self.int_b) % self.int_n if self.int_n > 0 else 0
+
+    @property
+    def hex_x(self) -> str:
+        return format(self.x, 'x').zfill(self.hex_digits)
+
+    def description(self) -> str:
+        return self.descr_tpl.format(self.test_name,
+                                     self.count,
+                                     self.int_a,
+                                     self.int_b,
+                                     self.int_n)
+
+    def arguments(self) -> List[str]:
+        return [bignum_common.quote_str(n) for n in [self.hex_a,
+                                                     self.hex_b,
+                                                     self.hex_n,
+                                                     self.hex_x]]
+
+    def result(self) -> List[str]:
+        return [self.hex_x]
+
+    @classmethod
+    def generate_function_tests(cls) -> Iterator[test_case.TestCase]:
+        for a_value, b_value in cls.get_value_pairs():
+            int_a = bignum_common.hex_to_int(a_value)
+            int_b = bignum_common.hex_to_int(b_value)
+            highest = max(int_a, int_b)
+
+            # Choose a modulus bigger then the arguments
+            for n_value in cls.modulus_values:
+                int_n = bignum_common.hex_to_int(n_value)
+                if highest < int_n:
+                    yield cls(n_value, a_value, b_value, cls.BITS_IN_LIMB).create_test_case()
+
 # END MERGE SLOT 2
 
 # BEGIN MERGE SLOT 3
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index c23cb6b3d9..0ef6fdbc4c 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -70,6 +70,7 @@ if(GEN_FILES)
             ${CMAKE_CURRENT_SOURCE_DIR}/../tests/scripts/generate_bignum_tests.py
             ${CMAKE_CURRENT_SOURCE_DIR}/../scripts/mbedtls_dev/bignum_common.py
             ${CMAKE_CURRENT_SOURCE_DIR}/../scripts/mbedtls_dev/bignum_core.py
+            ${CMAKE_CURRENT_SOURCE_DIR}/../scripts/mbedtls_dev/bignum_mod_raw.py
             ${CMAKE_CURRENT_SOURCE_DIR}/../scripts/mbedtls_dev/test_case.py
             ${CMAKE_CURRENT_SOURCE_DIR}/../scripts/mbedtls_dev/test_data_generation.py
     )
diff --git a/tests/Makefile b/tests/Makefile
index 7c08f54e14..0b31cdd076 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -94,6 +94,7 @@ $(GENERATED_BIGNUM_DATA_FILES): generated_bignum_test_data
 generated_bignum_test_data: scripts/generate_bignum_tests.py
 generated_bignum_test_data: ../scripts/mbedtls_dev/bignum_common.py
 generated_bignum_test_data: ../scripts/mbedtls_dev/bignum_core.py
+generated_bignum_test_data: ../scripts/mbedtls_dev/bignum_mod_raw.py
 generated_bignum_test_data: ../scripts/mbedtls_dev/test_case.py
 generated_bignum_test_data: ../scripts/mbedtls_dev/test_data_generation.py
 generated_bignum_test_data: