diff --git a/tests/suites/host_test.function b/tests/suites/host_test.function
index eb42a07..d28a75e 100644
--- a/tests/suites/host_test.function
+++ b/tests/suites/host_test.function
@@ -8,7 +8,7 @@
  *
  * \return      0 if success else 1
  */
-int verify_string(char **str)
+static int verify_string(char **str)
 {
     if ((*str)[0] != '"' ||
         (*str)[strlen(*str) - 1] != '"') {
@@ -32,7 +32,7 @@
  *
  * \return      0 if success else 1
  */
-int verify_int(char *str, intmax_t *p_value)
+static int verify_int(char *str, intmax_t *p_value)
 {
     char *end = NULL;
     errno = 0;
@@ -80,7 +80,7 @@
  *
  * \return      0 if success else -1
  */
-int get_line(FILE *f, char *buf, size_t len)
+static int get_line(FILE *f, char *buf, size_t len)
 {
     char *ret;
     int i = 0, str_len = 0, has_string = 0;
@@ -485,7 +485,7 @@
  *
  * \return      Program exit status.
  */
-int execute_tests(int argc, const char **argv)
+static int execute_tests(int argc, const char **argv)
 {
     /* Local Configurations and options */
     const char *default_filename = "DATA_FILE";
diff --git a/tests/suites/main_test.function b/tests/suites/main_test.function
index f327a03..c0cc2ac 100644
--- a/tests/suites/main_test.function
+++ b/tests/suites/main_test.function
@@ -69,7 +69,7 @@
  *
  * \return       0 if exp_id is found. 1 otherwise.
  */
-int get_expression(int32_t exp_id, intmax_t *out_value)
+static int get_expression(int32_t exp_id, intmax_t *out_value)
 {
     int ret = KEY_VALUE_MAPPING_FOUND;
 
@@ -100,7 +100,7 @@
  *
  * \return       DEPENDENCY_SUPPORTED if set else DEPENDENCY_NOT_SUPPORTED
  */
-int dep_check(int dep_id)
+static int dep_check(int dep_id)
 {
     int ret = DEPENDENCY_NOT_SUPPORTED;
 
@@ -155,7 +155,7 @@
  *               DISPATCH_TEST_FN_NOT_FOUND if not found
  *               DISPATCH_UNSUPPORTED_SUITE if not compile time enabled.
  */
-int dispatch_test(size_t func_idx, void **params)
+static int dispatch_test(size_t func_idx, void **params)
 {
     int ret = DISPATCH_TEST_SUCCESS;
     TestWrapper_t fp = NULL;
@@ -193,7 +193,7 @@
  *               DISPATCH_TEST_FN_NOT_FOUND if not found
  *               DISPATCH_UNSUPPORTED_SUITE if not compile time enabled.
  */
-int check_test(size_t func_idx)
+static int check_test(size_t func_idx)
 {
     int ret = DISPATCH_TEST_SUCCESS;
     TestWrapper_t fp = NULL;
diff --git a/tests/suites/test_suite_alignment.function b/tests/suites/test_suite_alignment.function
index 842101f..240f552 100644
--- a/tests/suites/test_suite_alignment.function
+++ b/tests/suites/test_suite_alignment.function
@@ -10,7 +10,7 @@
 /*
  * Convert a string of the form "abcd" (case-insensitive) to a uint64_t.
  */
-int parse_hex_string(char *hex_string, uint64_t *result)
+static int parse_hex_string(char *hex_string, uint64_t *result)
 {
     uint8_t raw[8] = { 0 };
     size_t olen;
diff --git a/tests/suites/test_suite_asn1parse.function b/tests/suites/test_suite_asn1parse.function
index 01a091b..394d08a 100644
--- a/tests/suites/test_suite_asn1parse.function
+++ b/tests/suites/test_suite_asn1parse.function
@@ -122,7 +122,7 @@
     return ERR_PARSE_INCONSISTENCY;
 }
 
-int get_len_step(const data_t *input, size_t buffer_size,
+static int get_len_step(const data_t *input, size_t buffer_size,
                  size_t actual_length)
 {
     unsigned char *buf = NULL;
diff --git a/tests/suites/test_suite_asn1write.function b/tests/suites/test_suite_asn1write.function
index 469b971..d332485 100644
--- a/tests/suites/test_suite_asn1write.function
+++ b/tests/suites/test_suite_asn1write.function
@@ -12,7 +12,7 @@
     size_t size;
 } generic_write_data_t;
 
-int generic_write_start_step(generic_write_data_t *data)
+static int generic_write_start_step(generic_write_data_t *data)
 {
     mbedtls_test_set_step(data->size);
     mbedtls_free(data->output);
@@ -26,7 +26,7 @@
     return 0;
 }
 
-int generic_write_finish_step(generic_write_data_t *data,
+static int generic_write_finish_step(generic_write_data_t *data,
                               const data_t *expected, int ret)
 {
     int ok = 0;
diff --git a/tests/suites/test_suite_bignum.function b/tests/suites/test_suite_bignum.function
index f3a64e1..22a637a 100644
--- a/tests/suites/test_suite_bignum.function
+++ b/tests/suites/test_suite_bignum.function
@@ -44,7 +44,7 @@
  * test) are stored in the data member of the state structure. Each number is in
  * the format that mbedtls_mpi_read_string understands and is chunk_len long.
  */
-int mbedtls_test_mpi_miller_rabin_determinizer(void *state,
+static int mbedtls_test_mpi_miller_rabin_determinizer(void *state,
                                                unsigned char *buf,
                                                size_t len)
 {
diff --git a/tests/suites/test_suite_cipher.function b/tests/suites/test_suite_cipher.function
index 8e49d2d..040c35c 100644
--- a/tests/suites/test_suite_cipher.function
+++ b/tests/suites/test_suite_cipher.function
@@ -129,7 +129,7 @@
  * return   1 if it is,
  *          0 if it isn't.
  */
-int buffer_is_all_zero(const uint8_t *buf, size_t size)
+static int buffer_is_all_zero(const uint8_t *buf, size_t size)
 {
     for (size_t i = 0; i < size; i++) {
         if (buf[i] != 0) {
diff --git a/tests/suites/test_suite_common.function b/tests/suites/test_suite_common.function
index 5c5700c..c508b11 100644
--- a/tests/suites/test_suite_common.function
+++ b/tests/suites/test_suite_common.function
@@ -1,7 +1,7 @@
 /* BEGIN_HEADER */
 #include "common.h"
 
-void fill_arrays(unsigned char *a, unsigned char *b, unsigned char *r1, unsigned char *r2, size_t n)
+static void fill_arrays(unsigned char *a, unsigned char *b, unsigned char *r1, unsigned char *r2, size_t n)
 {
     for (size_t i = 0; i < n; i++) {
         a[i]  = (unsigned char) i * 3;
diff --git a/tests/suites/test_suite_ctr_drbg.function b/tests/suites/test_suite_ctr_drbg.function
index 720eb3e..9fa55a7 100644
--- a/tests/suites/test_suite_ctr_drbg.function
+++ b/tests/suites/test_suite_ctr_drbg.function
@@ -96,6 +96,7 @@
 }
 
 static const int thread_random_reps = 10;
+void *thread_random_function(void *ctx); /* only used conditionally in ctr_drbg_threads */
 void *thread_random_function(void *ctx)
 {
     unsigned char out[16];
diff --git a/tests/suites/test_suite_debug.function b/tests/suites/test_suite_debug.function
index 70e7bad..878ceed 100644
--- a/tests/suites/test_suite_debug.function
+++ b/tests/suites/test_suite_debug.function
@@ -9,7 +9,7 @@
     char *ptr;
 };
 
-void string_debug(void *data, int level, const char *file, int line, const char *str)
+static void string_debug(void *data, int level, const char *file, int line, const char *str)
 {
     struct buffer_data *buffer = (struct buffer_data *) data;
     char *p = buffer->ptr;
diff --git a/tests/suites/test_suite_dhm.function b/tests/suites/test_suite_dhm.function
index 2090594..a7b4b40 100644
--- a/tests/suites/test_suite_dhm.function
+++ b/tests/suites/test_suite_dhm.function
@@ -1,7 +1,7 @@
 /* BEGIN_HEADER */
 #include "mbedtls/dhm.h"
 
-int check_get_value(const mbedtls_dhm_context *ctx,
+static int check_get_value(const mbedtls_dhm_context *ctx,
                     mbedtls_dhm_parameter param,
                     const mbedtls_mpi *expected)
 {
diff --git a/tests/suites/test_suite_entropy.function b/tests/suites/test_suite_entropy.function
index 5ac65fc..c89c26c 100644
--- a/tests/suites/test_suite_entropy.function
+++ b/tests/suites/test_suite_entropy.function
@@ -65,7 +65,7 @@
  */
 static unsigned char buffer_seed[MBEDTLS_ENTROPY_BLOCK_SIZE];
 
-int buffer_nv_seed_read(unsigned char *buf, size_t buf_len)
+static int buffer_nv_seed_read(unsigned char *buf, size_t buf_len)
 {
     if (buf_len != MBEDTLS_ENTROPY_BLOCK_SIZE) {
         return -1;
@@ -75,7 +75,7 @@
     return 0;
 }
 
-int buffer_nv_seed_write(unsigned char *buf, size_t buf_len)
+static int buffer_nv_seed_write(unsigned char *buf, size_t buf_len)
 {
     if (buf_len != MBEDTLS_ENTROPY_BLOCK_SIZE) {
         return -1;
@@ -111,7 +111,7 @@
     return 0;
 }
 
-int read_nv_seed(unsigned char *buf, size_t buf_len)
+static int read_nv_seed(unsigned char *buf, size_t buf_len)
 {
     FILE *f;
 
diff --git a/tests/suites/test_suite_lmots.function b/tests/suites/test_suite_lmots.function
index 293287a..61f2e28 100644
--- a/tests/suites/test_suite_lmots.function
+++ b/tests/suites/test_suite_lmots.function
@@ -3,7 +3,7 @@
 #include "mbedtls/lms.h"
 
 #if defined(MBEDTLS_TEST_HOOKS)
-int check_lmots_private_key_for_leak(unsigned char *sig)
+static int check_lmots_private_key_for_leak(unsigned char *sig)
 {
     size_t idx;
 
diff --git a/tests/suites/test_suite_pk.function b/tests/suites/test_suite_pk.function
index 38c27e3..c102f93 100644
--- a/tests/suites/test_suite_pk.function
+++ b/tests/suites/test_suite_pk.function
@@ -221,7 +221,7 @@
 }
 
 #if defined(MBEDTLS_PSA_CRYPTO_C)
-psa_status_t pk_psa_import_key(const unsigned char *key_data, size_t key_len,
+static psa_status_t pk_psa_import_key(const unsigned char *key_data, size_t key_len,
                                psa_key_type_t type, psa_key_usage_t usage,
                                psa_algorithm_t alg, mbedtls_svc_key_id_t *key)
 {
@@ -320,7 +320,7 @@
  *                              for volatile keys.
  * \param[out] key              Identifier of the "generated" (actually imported) PSA key.
  */
-psa_status_t pk_psa_setup(psa_key_type_t type, size_t bits,
+static psa_status_t pk_psa_setup(psa_key_type_t type, size_t bits,
                           psa_key_usage_t usage, psa_algorithm_t alg,
                           psa_algorithm_t enrollment_alg,
                           mbedtls_svc_key_id_t persistent_key_id,
@@ -468,7 +468,7 @@
 #endif /* MBEDTLS_PSA_CRYPTO_C */
 
 #if defined(MBEDTLS_RSA_C)
-int mbedtls_rsa_decrypt_func(void *ctx, size_t *olen,
+static int mbedtls_rsa_decrypt_func(void *ctx, size_t *olen,
                              const unsigned char *input, unsigned char *output,
                              size_t output_max_len)
 {
@@ -476,7 +476,7 @@
                                      mbedtls_test_rnd_std_rand, NULL,
                                      olen, input, output, output_max_len);
 }
-int mbedtls_rsa_sign_func(void *ctx,
+static int mbedtls_rsa_sign_func(void *ctx,
                           int (*f_rng)(void *, unsigned char *, size_t), void *p_rng,
                           mbedtls_md_type_t md_alg, unsigned int hashlen,
                           const unsigned char *hash, unsigned char *sig)
@@ -487,7 +487,7 @@
                                   mbedtls_test_rnd_std_rand, NULL,
                                   md_alg, hashlen, hash, sig);
 }
-size_t mbedtls_rsa_key_len_func(void *ctx)
+static size_t mbedtls_rsa_key_len_func(void *ctx)
 {
     return ((const mbedtls_rsa_context *) ctx)->len;
 }
@@ -618,7 +618,7 @@
 
 /* Create a copy of a PSA key with same usage and algorithm policy and destroy
  * the original one. */
-mbedtls_svc_key_id_t psa_copy_and_destroy(mbedtls_svc_key_id_t orig_key_id)
+static mbedtls_svc_key_id_t psa_copy_and_destroy(mbedtls_svc_key_id_t orig_key_id)
 {
     psa_key_attributes_t orig_attr = PSA_KEY_ATTRIBUTES_INIT;
     psa_key_attributes_t new_attr = PSA_KEY_ATTRIBUTES_INIT;
diff --git a/tests/suites/test_suite_pkcs7.function b/tests/suites/test_suite_pkcs7.function
index 4c8bf23..e5dc4bd 100644
--- a/tests/suites/test_suite_pkcs7.function
+++ b/tests/suites/test_suite_pkcs7.function
@@ -17,7 +17,7 @@
  * END_DEPENDENCIES
  */
 /* BEGIN_SUITE_HELPERS */
-int pkcs7_parse_buffer(unsigned char *pkcs7_buf, int buflen)
+static int pkcs7_parse_buffer(unsigned char *pkcs7_buf, int buflen)
 {
     int res;
     mbedtls_pkcs7 pkcs7;
diff --git a/tests/suites/test_suite_platform.function b/tests/suites/test_suite_platform.function
index c65d011..5d49e52 100644
--- a/tests/suites/test_suite_platform.function
+++ b/tests/suites/test_suite_platform.function
@@ -18,7 +18,7 @@
 #else
 #include <unistd.h>
 #endif
-void sleep_ms(int milliseconds)
+static void sleep_ms(int milliseconds)
 {
 #if defined(_WIN32) || defined(WIN32) || defined(__CYGWIN__) || \
     defined(__MINGW32__) || defined(_WIN64)
diff --git a/tests/suites/test_suite_psa_crypto.function b/tests/suites/test_suite_psa_crypto.function
index 85b2fd7..144c2e5 100644
--- a/tests/suites/test_suite_psa_crypto.function
+++ b/tests/suites/test_suite_psa_crypto.function
@@ -153,7 +153,7 @@
 }
 #endif /* MBEDTLS_ASN1_WRITE_C */
 
-int exercise_mac_setup(psa_key_type_t key_type,
+static int exercise_mac_setup(psa_key_type_t key_type,
                        const unsigned char *key_bytes,
                        size_t key_length,
                        psa_algorithm_t alg,
@@ -185,7 +185,7 @@
     return 0;
 }
 
-int exercise_cipher_setup(psa_key_type_t key_type,
+static int exercise_cipher_setup(psa_key_type_t key_type,
                           const unsigned char *key_bytes,
                           size_t key_length,
                           psa_algorithm_t alg,
@@ -1332,7 +1332,7 @@
 /* Attempt to import the key in ctx. This handles any valid error codes
  * and reports an error for any invalid codes. This function also insures
  * that once imported by some thread, all threads can use the key. */
-void *thread_import_key(void *ctx)
+static void *thread_import_key(void *ctx)
 {
     mbedtls_svc_key_id_t returned_key_id;
     same_key_context *skc = (struct same_key_context *) ctx;
@@ -1406,7 +1406,7 @@
     return NULL;
 }
 
-void *thread_use_and_destroy_key(void *ctx)
+static void *thread_use_and_destroy_key(void *ctx)
 {
     same_key_context *skc = (struct same_key_context *) ctx;
 
@@ -1446,7 +1446,7 @@
     int reps;
 }
 generate_key_context;
-void *thread_generate_key(void *ctx)
+static void *thread_generate_key(void *ctx)
 {
     mbedtls_svc_key_id_t key = MBEDTLS_SVC_KEY_ID_INIT;
     psa_key_attributes_t got_attributes = PSA_KEY_ATTRIBUTES_INIT;
diff --git a/tests/suites/test_suite_psa_crypto_metadata.function b/tests/suites/test_suite_psa_crypto_metadata.function
index b51f2a2..d299794 100644
--- a/tests/suites/test_suite_psa_crypto_metadata.function
+++ b/tests/suites/test_suite_psa_crypto_metadata.function
@@ -106,7 +106,7 @@
  * The expected parity is even so that 0 is considered a valid encoding.
  *
  * Return a nonzero value if value has even parity and 0 otherwise. */
-int has_even_parity(uint32_t value)
+static int has_even_parity(uint32_t value)
 {
     value ^= value >> 16;
     value ^= value >> 8;
@@ -116,7 +116,7 @@
 #define TEST_PARITY(value)                    \
     TEST_ASSERT(has_even_parity(value))
 
-void algorithm_classification(psa_algorithm_t alg, unsigned flags)
+static void algorithm_classification(psa_algorithm_t alg, unsigned flags)
 {
     unsigned classification_flags_tested = 0;
     TEST_CLASSIFICATION_MACRO(1, ALG_IS_VENDOR_DEFINED, alg, flags);
@@ -155,7 +155,7 @@
 exit:;
 }
 
-void key_type_classification(psa_key_type_t type, unsigned flags)
+static void key_type_classification(psa_key_type_t type, unsigned flags)
 {
     unsigned classification_flags_tested = 0;
 
@@ -192,7 +192,7 @@
 exit:;
 }
 
-void mac_algorithm_core(psa_algorithm_t alg, int classification_flags,
+static void mac_algorithm_core(psa_algorithm_t alg, int classification_flags,
                         psa_key_type_t key_type, size_t key_bits,
                         size_t length)
 {
@@ -218,7 +218,7 @@
 exit:;
 }
 
-void aead_algorithm_core(psa_algorithm_t alg, int classification_flags,
+static void aead_algorithm_core(psa_algorithm_t alg, int classification_flags,
                          psa_key_type_t key_type, size_t key_bits,
                          size_t tag_length)
 {
diff --git a/tests/suites/test_suite_psa_crypto_se_driver_hal.function b/tests/suites/test_suite_psa_crypto_se_driver_hal.function
index 37a72d9..96be55b 100644
--- a/tests/suites/test_suite_psa_crypto_se_driver_hal.function
+++ b/tests/suites/test_suite_psa_crypto_se_driver_hal.function
@@ -599,7 +599,7 @@
  * If this changes, the storage format version must change.
  * See psa_get_se_driver_its_file_uid() in psa_crypto_se.c.
  */
-psa_storage_uid_t file_uid_for_location(psa_key_location_t location)
+static psa_storage_uid_t file_uid_for_location(psa_key_location_t location)
 {
     if (location > PSA_MAX_SE_LOCATION) {
         return 0;
diff --git a/tests/suites/test_suite_psa_crypto_se_driver_hal_mocks.function b/tests/suites/test_suite_psa_crypto_se_driver_hal_mocks.function
index b6d3a34..9480bd4 100644
--- a/tests/suites/test_suite_psa_crypto_se_driver_hal_mocks.function
+++ b/tests/suites/test_suite_psa_crypto_se_driver_hal_mocks.function
@@ -162,7 +162,7 @@
     return mock_import_data.return_value;
 }
 
-psa_status_t mock_export(psa_drv_se_context_t *context,
+static psa_status_t mock_export(psa_drv_se_context_t *context,
                          psa_key_slot_number_t slot_number,
                          uint8_t *p_data,
                          size_t data_size,
@@ -179,7 +179,7 @@
     return mock_export_data.return_value;
 }
 
-psa_status_t mock_export_public(psa_drv_se_context_t *context,
+static psa_status_t mock_export_public(psa_drv_se_context_t *context,
                                 psa_key_slot_number_t slot_number,
                                 uint8_t *p_data,
                                 size_t data_size,
@@ -196,7 +196,7 @@
     return mock_export_public_data.return_value;
 }
 
-psa_status_t mock_sign(psa_drv_se_context_t *context,
+static psa_status_t mock_sign(psa_drv_se_context_t *context,
                        psa_key_slot_number_t key_slot,
                        psa_algorithm_t alg,
                        const uint8_t *p_hash,
@@ -219,7 +219,7 @@
     return mock_sign_data.return_value;
 }
 
-psa_status_t mock_verify(psa_drv_se_context_t *context,
+static psa_status_t mock_verify(psa_drv_se_context_t *context,
                          psa_key_slot_number_t key_slot,
                          psa_algorithm_t alg,
                          const uint8_t *p_hash,
@@ -240,7 +240,7 @@
     return mock_verify_data.return_value;
 }
 
-psa_status_t mock_allocate(psa_drv_se_context_t *drv_context,
+static psa_status_t mock_allocate(psa_drv_se_context_t *drv_context,
                            void *persistent_data,
                            const psa_key_attributes_t *attributes,
                            psa_key_creation_method_t method,
@@ -258,7 +258,7 @@
     return mock_allocate_data.return_value;
 }
 
-psa_status_t mock_destroy(psa_drv_se_context_t *context,
+static psa_status_t mock_destroy(psa_drv_se_context_t *context,
                           void *persistent_data,
                           psa_key_slot_number_t slot_number)
 {
diff --git a/tests/suites/test_suite_x509parse.function b/tests/suites/test_suite_x509parse.function
index ba71c8f..e72a6e3 100644
--- a/tests/suites/test_suite_x509parse.function
+++ b/tests/suites/test_suite_x509parse.function
@@ -60,7 +60,7 @@
     1024,
 };
 
-int verify_none(void *data, mbedtls_x509_crt *crt, int certificate_depth, uint32_t *flags)
+static int verify_none(void *data, mbedtls_x509_crt *crt, int certificate_depth, uint32_t *flags)
 {
     ((void) data);
     ((void) crt);
@@ -70,7 +70,7 @@
     return 0;
 }
 
-int verify_all(void *data, mbedtls_x509_crt *crt, int certificate_depth, uint32_t *flags)
+static int verify_all(void *data, mbedtls_x509_crt *crt, int certificate_depth, uint32_t *flags)
 {
     ((void) data);
     ((void) crt);
@@ -81,7 +81,7 @@
 }
 
 #if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK)
-int ca_callback_fail(void *data, mbedtls_x509_crt const *child, mbedtls_x509_crt **candidates)
+static int ca_callback_fail(void *data, mbedtls_x509_crt const *child, mbedtls_x509_crt **candidates)
 {
     ((void) data);
     ((void) child);
@@ -90,7 +90,7 @@
     return -1;
 }
 #if defined(MBEDTLS_X509_CRT_PARSE_C)
-int ca_callback(void *data, mbedtls_x509_crt const *child,
+static int ca_callback(void *data, mbedtls_x509_crt const *child,
                 mbedtls_x509_crt **candidates)
 {
     int ret = 0;
@@ -141,7 +141,7 @@
 #endif /* MBEDTLS_X509_CRT_PARSE_C */
 #endif /* MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK */
 
-int verify_fatal(void *data, mbedtls_x509_crt *crt, int certificate_depth, uint32_t *flags)
+static int verify_fatal(void *data, mbedtls_x509_crt *crt, int certificate_depth, uint32_t *flags)
 {
     int *levels = (int *) data;
 
@@ -158,7 +158,7 @@
 }
 
 /* strsep() not available on Windows */
-char *mystrsep(char **stringp, const char *delim)
+static char *mystrsep(char **stringp, const char *delim)
 {
     const char *p;
     char *ret = *stringp;
@@ -192,13 +192,13 @@
     char *p;
 } verify_print_context;
 
-void verify_print_init(verify_print_context *ctx)
+static void verify_print_init(verify_print_context *ctx)
 {
     memset(ctx, 0, sizeof(verify_print_context));
     ctx->p = ctx->buf;
 }
 
-int verify_print(void *data, mbedtls_x509_crt *crt, int certificate_depth, uint32_t *flags)
+static int verify_print(void *data, mbedtls_x509_crt *crt, int certificate_depth, uint32_t *flags)
 {
     int ret;
     verify_print_context *ctx = (verify_print_context *) data;
@@ -226,7 +226,7 @@
     return 0;
 }
 
-int verify_parse_san(mbedtls_x509_subject_alternative_name *san,
+static int verify_parse_san(mbedtls_x509_subject_alternative_name *san,
                      char **buf, size_t *size)
 {
     int ret;
@@ -317,7 +317,7 @@
     return 0;
 }
 
-int parse_crt_ext_cb(void *p_ctx, mbedtls_x509_crt const *crt, mbedtls_x509_buf const *oid,
+static int parse_crt_ext_cb(void *p_ctx, mbedtls_x509_crt const *crt, mbedtls_x509_buf const *oid,
                      int critical, const unsigned char *cp, const unsigned char *end)
 {
     (void) crt;
@@ -417,7 +417,7 @@
 #endif /* MBEDTLS_X509_CRT_PARSE_C */
 
 #if defined(MBEDTLS_X509_CSR_PARSE_C)
-int parse_csr_ext_accept_cb(void *p_ctx, mbedtls_x509_csr const *csr, mbedtls_x509_buf const *oid,
+static int parse_csr_ext_accept_cb(void *p_ctx, mbedtls_x509_csr const *csr, mbedtls_x509_buf const *oid,
                             int critical, const unsigned char *cp, const unsigned char *end)
 {
     (void) p_ctx;
@@ -430,7 +430,7 @@
     return 0;
 }
 
-int parse_csr_ext_reject_cb(void *p_ctx, mbedtls_x509_csr const *csr, mbedtls_x509_buf const *oid,
+static int parse_csr_ext_reject_cb(void *p_ctx, mbedtls_x509_csr const *csr, mbedtls_x509_buf const *oid,
                             int critical, const unsigned char *cp, const unsigned char *end)
 {
     (void) p_ctx;
diff --git a/tests/suites/test_suite_x509write.function b/tests/suites/test_suite_x509write.function
index 1db7e1c..820b48d 100644
--- a/tests/suites/test_suite_x509write.function
+++ b/tests/suites/test_suite_x509write.function
@@ -11,14 +11,14 @@
 #include "mbedtls/psa_util.h"
 
 #if defined(MBEDTLS_RSA_C)
-int mbedtls_rsa_decrypt_func(void *ctx, size_t *olen,
+static int mbedtls_rsa_decrypt_func(void *ctx, size_t *olen,
                              const unsigned char *input, unsigned char *output,
                              size_t output_max_len)
 {
     return mbedtls_rsa_pkcs1_decrypt((mbedtls_rsa_context *) ctx, NULL, NULL,
                                      olen, input, output, output_max_len);
 }
-int mbedtls_rsa_sign_func(void *ctx,
+static int mbedtls_rsa_sign_func(void *ctx,
                           int (*f_rng)(void *, unsigned char *, size_t), void *p_rng,
                           mbedtls_md_type_t md_alg, unsigned int hashlen,
                           const unsigned char *hash, unsigned char *sig)
@@ -26,7 +26,7 @@
     return mbedtls_rsa_pkcs1_sign((mbedtls_rsa_context *) ctx, f_rng, p_rng,
                                   md_alg, hashlen, hash, sig);
 }
-size_t mbedtls_rsa_key_len_func(void *ctx)
+static size_t mbedtls_rsa_key_len_func(void *ctx)
 {
     return ((const mbedtls_rsa_context *) ctx)->len;
 }