diff --git a/tests/include/test/arguments.h b/tests/include/test/arguments.h
new file mode 100644
index 0000000..8c7dd5a
--- /dev/null
+++ b/tests/include/test/arguments.h
@@ -0,0 +1,43 @@
+/**
+ * \file arguments.h
+ *
+ * \brief Manipulation of test arguments.
+ *
+ * Much of the code is in host_test.function, to be migrated here later.
+ */
+
+/*
+ *  Copyright The Mbed TLS Contributors
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *  not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+#ifndef TEST_ARGUMENTS_H
+#define TEST_ARGUMENTS_H
+
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "mbedtls/config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
+#include <stdint.h>
+#include <stdlib.h>
+
+typedef union {
+    size_t len;
+    int32_t s32;
+} mbedtls_test_argument_t;
+
+#endif /* TEST_ARGUMENTS_H */
diff --git a/tests/scripts/generate_test_code.py b/tests/scripts/generate_test_code.py
index 6b5f11b..54c7e3a 100755
--- a/tests/scripts/generate_test_code.py
+++ b/tests/scripts/generate_test_code.py
@@ -471,7 +471,7 @@
             continue
         if re.search(INT_CHECK_REGEX, arg.strip()):
             args.append('int')
-            args_dispatch.append('*( (int *) params[%d] )' % arg_idx)
+            args_dispatch.append('((mbedtls_test_argument_t*)params[%d])->s32' % arg_idx)
         elif re.search(CHAR_CHECK_REGEX, arg.strip()):
             args.append('char*')
             args_dispatch.append('(char *) params[%d]' % arg_idx)
@@ -479,7 +479,7 @@
             args.append('hex')
             # create a structure
             pointer_initializer = '(uint8_t *) params[%d]' % arg_idx
-            len_initializer = '*( (uint32_t *) params[%d] )' % (arg_idx+1)
+            len_initializer = '((mbedtls_test_argument_t*)params[%d])->len' % (arg_idx+1)
             local_vars += """    data_t data%d = {%s, %s};
 """ % (arg_idx, pointer_initializer, len_initializer)
 
diff --git a/tests/scripts/test_generate_test_code.py b/tests/scripts/test_generate_test_code.py
index 9a78ca1..c198ad0 100755
--- a/tests/scripts/test_generate_test_code.py
+++ b/tests/scripts/test_generate_test_code.py
@@ -485,9 +485,10 @@
         args, local, arg_dispatch = parse_function_arguments(line)
         self.assertEqual(args, ['char*', 'int', 'int'])
         self.assertEqual(local, '')
-        self.assertEqual(arg_dispatch, ['(char *) params[0]',
-                                        '*( (int *) params[1] )',
-                                        '*( (int *) params[2] )'])
+        self.assertEqual(arg_dispatch,
+                         ['(char *) params[0]',
+                          '((mbedtls_test_argument_t*)params[1])->s32',
+                          '((mbedtls_test_argument_t*)params[2])->s32'])
 
     def test_hex_params(self):
         """
@@ -499,10 +500,10 @@
         self.assertEqual(args, ['char*', 'hex', 'int'])
         self.assertEqual(local,
                          '    data_t data1 = {(uint8_t *) params[1], '
-                         '*( (uint32_t *) params[2] )};\n')
+                         '((mbedtls_test_argument_t*)params[2])->len};\n')
         self.assertEqual(arg_dispatch, ['(char *) params[0]',
                                         '&data1',
-                                        '*( (int *) params[3] )'])
+                                        '((mbedtls_test_argument_t*)params[3])->s32'])
 
     def test_unsupported_arg(self):
         """
diff --git a/tests/suites/helpers.function b/tests/suites/helpers.function
index 6af48c4..12828f5 100644
--- a/tests/suites/helpers.function
+++ b/tests/suites/helpers.function
@@ -2,8 +2,9 @@
 /*----------------------------------------------------------------------------*/
 /* Headers */
 
-#include <test/macros.h>
+#include <test/arguments.h>
 #include <test/helpers.h>
+#include <test/macros.h>
 #include <test/random.h>
 #include <test/psa_crypto_helpers.h>
 
diff --git a/tests/suites/host_test.function b/tests/suites/host_test.function
index 565ded3..59b18d2 100644
--- a/tests/suites/host_test.function
+++ b/tests/suites/host_test.function
@@ -28,7 +28,7 @@
  *              integer value.
  *
  * \param str   Input string.
- * \param value Pointer to int for output value.
+ * \param p_value Pointer to output value.
  *
  * \return      0 if success else 1
  */
@@ -203,7 +203,8 @@
  *
  * \return      0 for success else 1
  */
-static int convert_params(size_t cnt, char **params, int32_t *int_params_store)
+static int convert_params(size_t cnt, char **params,
+                          mbedtls_test_argument_t *int_params_store)
 {
     char **cur = params;
     char **out = params;
@@ -221,7 +222,7 @@
                 break;
             }
         } else if (strcmp(type, "int") == 0) {
-            if (verify_int(val, int_params_store) == 0) {
+            if (verify_int(val, &int_params_store->s32) == 0) {
                 *out++ = (char *) int_params_store++;
             } else {
                 ret = (DISPATCH_INVALID_TEST_DATA);
@@ -235,7 +236,7 @@
                     mbedtls_test_unhexify((unsigned char *) val, strlen(val),
                                           val, &len) == 0);
 
-                *int_params_store = len;
+                int_params_store->len = len;
                 *out++ = val;
                 *out++ = (char *) (int_params_store++);
             } else {
@@ -244,7 +245,7 @@
             }
         } else if (strcmp(type, "exp") == 0) {
             int exp_id = strtol(val, NULL, 10);
-            if (get_expression(exp_id, int_params_store) == 0) {
+            if (get_expression(exp_id, &int_params_store->s32) == 0) {
                 *out++ = (char *) int_params_store++;
             } else {
                 ret = (DISPATCH_INVALID_TEST_DATA);
@@ -463,7 +464,7 @@
     char buf[5000];
     char *params[50];
     /* Store for processed integer params. */
-    int32_t int_params[50];
+    mbedtls_test_argument_t int_params[50];
     void *pointer;
 #if defined(__unix__) || (defined(__APPLE__) && defined(__MACH__))
     int stdout_fd = -1;