diff --git a/include/polarssl/ssl_ciphersuites.h b/include/polarssl/ssl_ciphersuites.h
index 5ecd5fe..c4f1ffe 100644
--- a/include/polarssl/ssl_ciphersuites.h
+++ b/include/polarssl/ssl_ciphersuites.h
@@ -233,6 +233,7 @@
 #define TLS_ECDHE_ECDSA_WITH_AES_128_CCM_8      0xC0AE  /**< TLS 1.2 */
 #define TLS_ECDHE_ECDSA_WITH_AES_256_CCM_8      0xC0AF  /**< TLS 1.2 */
 
+/* Reminder: update _ssl_premaster_secret when adding a new key exchange */
 typedef enum {
     POLARSSL_KEY_EXCHANGE_NONE = 0,
     POLARSSL_KEY_EXCHANGE_RSA,