diff --git a/tests/suites/test_suite_psa_crypto.function b/tests/suites/test_suite_psa_crypto.function
index 87bf9b3..6c53476 100644
--- a/tests/suites/test_suite_psa_crypto.function
+++ b/tests/suites/test_suite_psa_crypto.function
@@ -3480,7 +3480,8 @@
     psa_mac_operation_t operation = psa_mac_operation_init_short();
     psa_status_t status = PSA_ERROR_GENERIC_ERROR;
 #if defined(KNOWN_SUPPORTED_MAC_ALG)
-    const uint8_t smoke_test_key_data[16] = "kkkkkkkkkkkkkkkk";
+    /* We need to tell the compiler that we meant to leave out the null character. */
+    const uint8_t smoke_test_key_data[16] __attribute__ ((nonstring)) = "kkkkkkkkkkkkkkkk";
 #endif
 
     PSA_ASSERT(psa_crypto_init());
@@ -3917,7 +3918,8 @@
     psa_cipher_operation_t operation = psa_cipher_operation_init_short();
     psa_status_t status;
 #if defined(KNOWN_SUPPORTED_CIPHER_ALG)
-    const uint8_t smoke_test_key_data[16] = "kkkkkkkkkkkkkkkk";
+    /* We need to tell the compiler that we meant to leave out the null character. */
+    const uint8_t smoke_test_key_data[16] __attribute__ ((nonstring)) = "kkkkkkkkkkkkkkkk";
 #endif
 
     PSA_ASSERT(psa_crypto_init());
diff --git a/tests/suites/test_suite_psa_crypto_slot_management.function b/tests/suites/test_suite_psa_crypto_slot_management.function
index 604c4bd..4177a05 100644
--- a/tests/suites/test_suite_psa_crypto_slot_management.function
+++ b/tests/suites/test_suite_psa_crypto_slot_management.function
@@ -377,8 +377,9 @@
     mbedtls_svc_key_id_t returned_id = MBEDTLS_SVC_KEY_ID_INIT;
     psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
     psa_key_type_t type1 = PSA_KEY_TYPE_RAW_DATA;
-    const uint8_t material1[5] = "a key";
-    const uint8_t material2[5] = "b key";
+    /* We need to tell the compiler that we meant to leave out the null character. */
+    const uint8_t material1[5] __attribute__ ((nonstring)) = "a key";
+    const uint8_t material2[5] __attribute__ ((nonstring)) = "b key";
     size_t bits1 = PSA_BYTES_TO_BITS(sizeof(material1));
     uint8_t reexported[sizeof(material1)];
     size_t reexported_length;
@@ -747,7 +748,7 @@
     psa_key_id_t key_id;
     psa_status_t close_status = close_status_arg;
     psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
-    uint8_t material[1] = "a";
+    uint8_t material[1] = { 'a' };
 
     PSA_ASSERT(psa_crypto_init());
 
diff --git a/tests/suites/test_suite_ssl_decrypt.function b/tests/suites/test_suite_ssl_decrypt.function
index 35f0adb..46f9617 100644
--- a/tests/suites/test_suite_ssl_decrypt.function
+++ b/tests/suites/test_suite_ssl_decrypt.function
@@ -37,7 +37,8 @@
     mbedtls_ssl_write_version(rec_good.ver,
                               MBEDTLS_SSL_TRANSPORT_STREAM,
                               version);
-    const char sample_plaintext[3] = "ABC";
+    /* We need to tell the compiler that we meant to leave out the null character. */
+    const char sample_plaintext[3] __attribute__ ((nonstring)) = "ABC";
     mbedtls_ssl_context ssl;
     mbedtls_ssl_init(&ssl);
     uint8_t *buf = NULL;