diff --git a/include/polarssl/ssl_ciphersuites.h b/include/polarssl/ssl_ciphersuites.h
index c4f1ffe..191596f 100644
--- a/include/polarssl/ssl_ciphersuites.h
+++ b/include/polarssl/ssl_ciphersuites.h
@@ -233,7 +233,9 @@
 #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 */
+/* Reminder: update _ssl_premaster_secret when adding a new key exchange.
+ * Reminder: update POLARSSL_KEY_EXCHANGE__WITH_CERT__ENABLED below.
+ */
 typedef enum {
     POLARSSL_KEY_EXCHANGE_NONE = 0,
     POLARSSL_KEY_EXCHANGE_RSA,
@@ -248,6 +250,17 @@
     POLARSSL_KEY_EXCHANGE_ECDH_ECDSA,
 } key_exchange_type_t;
 
+#if defined(POLARSSL_KEY_EXCHANGE_RSA_ENABLED)          || \
+    defined(POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED)      || \
+    defined(POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED)    || \
+    defined(POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)  || \
+    defined(POLARSSL_KEY_EXCHANGE_RSA_PSK_ENABLED)      || \
+    defined(POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED)    || \
+    defined(POLARSSL_KEY_EXCHANGE_ECDH_RSA_ENABLED)     || \
+    defined(POLARSSL_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
+#define POLARSSL_KEY_EXCHANGE__WITH_CERT__ENABLED
+#endif
+
 typedef struct _ssl_ciphersuite_t ssl_ciphersuite_t;
 
 #define POLARSSL_CIPHERSUITE_WEAK       0x01    /**< Weak ciphersuite flag  */