diff --git a/tests/suites/test_suite_ctr_drbg.function b/tests/suites/test_suite_ctr_drbg.function
index 4c6ee6f5a6..a4627de58b 100644
--- a/tests/suites/test_suite_ctr_drbg.function
+++ b/tests/suites/test_suite_ctr_drbg.function
@@ -31,15 +31,13 @@ static void ctr_drbg_validate_internal(int reseed_mode, data_t *nonce,
                                        data_t *result)
 {
     mbedtls_ctr_drbg_context ctx;
+    mbedtls_ctr_drbg_init(&ctx);
     unsigned char buf[64];
 
     size_t entropy_chunk_len = (size_t) entropy_len_arg;
-
     TEST_ASSERT(entropy_chunk_len <= sizeof(buf));
 
     test_offset_idx = 0;
-    mbedtls_ctr_drbg_init(&ctx);
-
     test_max_idx = entropy->len;
 
     /* CTR_DRBG_Instantiate(entropy[:entropy->len], nonce, perso, <ignored>)
diff --git a/tests/suites/test_suite_pkwrite.function b/tests/suites/test_suite_pkwrite.function
index d1f7813b73..97fd92a5bd 100644
--- a/tests/suites/test_suite_pkwrite.function
+++ b/tests/suites/test_suite_pkwrite.function
@@ -31,13 +31,13 @@ static void fix_new_lines(unsigned char *in_str, size_t *len)
 static void pk_write_check_common(char *key_file, int is_public_key, int is_der)
 {
     mbedtls_pk_context key;
+    mbedtls_pk_init(&key);
     unsigned char *buf = NULL;
     unsigned char *check_buf = NULL;
     unsigned char *start_buf;
     size_t buf_len, check_buf_len;
     int ret;
 
-    mbedtls_pk_init(&key);
     USE_PSA_INIT();
 
     /* Note: if mbedtls_pk_load_file() successfully reads the file, then
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 15232a44f7..ff0ccdd092 100644
--- a/tests/suites/test_suite_psa_crypto_se_driver_hal.function
+++ b/tests/suites/test_suite_psa_crypto_se_driver_hal.function
@@ -1290,7 +1290,7 @@ void sign_verify(int flow,
     mbedtls_svc_key_id_t returned_id;
     mbedtls_svc_key_id_t sw_key = MBEDTLS_SVC_KEY_ID_INIT;
     psa_key_attributes_t sw_attributes = PSA_KEY_ATTRIBUTES_INIT;
-    psa_key_attributes_t drv_attributes;
+    psa_key_attributes_t drv_attributes = PSA_KEY_ATTRIBUTES_INIT;
     uint8_t signature[PSA_SIGNATURE_MAX_SIZE];
     size_t signature_length;
 
diff --git a/tests/suites/test_suite_ssl.function b/tests/suites/test_suite_ssl.function
index 0a35aa9734..19a9f32098 100644
--- a/tests/suites/test_suite_ssl.function
+++ b/tests/suites/test_suite_ssl.function
@@ -19,6 +19,7 @@ void test_callback_buffer_sanity()
 {
     enum { MSGLEN = 10 };
     mbedtls_test_ssl_buffer buf;
+    mbedtls_test_ssl_buffer_init(&buf);
     unsigned char input[MSGLEN];
     unsigned char output[MSGLEN];
 
@@ -38,8 +39,6 @@ void test_callback_buffer_sanity()
 
     /* Make sure calling put and get on a buffer that hasn't been set up results
      * in error. */
-    mbedtls_test_ssl_buffer_init(&buf);
-
     TEST_ASSERT(mbedtls_test_ssl_buffer_put(&buf, input, sizeof(input))
                 == -1);
     TEST_ASSERT(mbedtls_test_ssl_buffer_get(&buf, output, sizeof(output))
diff --git a/tests/suites/test_suite_x509write.function b/tests/suites/test_suite_x509write.function
index b4509e235c..ad0f2a6f59 100644
--- a/tests/suites/test_suite_x509write.function
+++ b/tests/suites/test_suite_x509write.function
@@ -457,16 +457,16 @@ void mbedtls_x509_string_to_names(char *name, char *parsed_name, int result
     int ret;
     size_t len = 0;
     mbedtls_asn1_named_data *names = NULL;
-    mbedtls_x509_name parsed, *parsed_cur, *parsed_prv;
-    unsigned char buf[1024], out[1024], *c;
+    mbedtls_x509_name parsed;
+    memset(&parsed, 0, sizeof(parsed));
+    mbedtls_x509_name *parsed_cur = NULL;
+    mbedtls_x509_name *parsed_prv = NULL;
+    unsigned char buf[1024] = { 0 };
+    unsigned char out[1024] = { 0 };
+    unsigned char *c = buf + sizeof(buf);
 
     USE_PSA_INIT();
 
-    memset(&parsed, 0, sizeof(parsed));
-    memset(out, 0, sizeof(out));
-    memset(buf, 0, sizeof(buf));
-    c = buf + sizeof(buf);
-
     ret = mbedtls_x509_string_to_names(&names, name);
     TEST_ASSERT(ret == result);