diff --git a/library/ssl_tls13_keys.c b/library/ssl_tls13_keys.c
index 18997e9..afd84a9 100644
--- a/library/ssl_tls13_keys.c
+++ b/library/ssl_tls13_keys.c
@@ -1559,8 +1559,7 @@
 
 cleanup:
     if (shared_secret != NULL) {
-        mbedtls_platform_zeroize(shared_secret, shared_secret_len);
-        mbedtls_free(shared_secret);
+        mbedtls_zeroize_and_free(shared_secret, shared_secret_len);
     }
 
     return ret;