diff --git a/library/ssl_tls13_server.c b/library/ssl_tls13_server.c
index 2883328..598ca91 100644
--- a/library/ssl_tls13_server.c
+++ b/library/ssl_tls13_server.c
@@ -934,6 +934,7 @@
     return( masked == exts_mask );
 }
 
+#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED)
 MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_tls13_client_hello_has_exts_for_ephemeral_key_exchange(
         mbedtls_ssl_context *ssl )
@@ -944,8 +945,9 @@
                 MBEDTLS_SSL_EXT_MASK( KEY_SHARE )        |
                 MBEDTLS_SSL_EXT_MASK( SIG_ALG ) ) );
 }
+#endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED */
 
-#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED)
+#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ENABLED)
 MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_tls13_client_hello_has_exts_for_psk_key_exchange(
                mbedtls_ssl_context *ssl )
@@ -955,7 +957,9 @@
                 MBEDTLS_SSL_EXT_MASK( PRE_SHARED_KEY )          |
                 MBEDTLS_SSL_EXT_MASK( PSK_KEY_EXCHANGE_MODES ) ) );
 }
+#endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ENABLED */
 
+#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL_ENABLED)
 MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_tls13_client_hello_has_exts_for_psk_ephemeral_key_exchange(
                mbedtls_ssl_context *ssl )
@@ -967,19 +971,24 @@
                 MBEDTLS_SSL_EXT_MASK( PRE_SHARED_KEY )          |
                 MBEDTLS_SSL_EXT_MASK( PSK_KEY_EXCHANGE_MODES ) ) );
 }
-#endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED */
+#endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL_ENABLED */
 
 MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_tls13_check_ephemeral_key_exchange( mbedtls_ssl_context *ssl )
 {
+#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED)
     return( mbedtls_ssl_conf_tls13_ephemeral_enabled( ssl ) &&
             ssl_tls13_client_hello_has_exts_for_ephemeral_key_exchange( ssl ) );
+#else
+    ((void) ssl);
+    return( 0 );
+#endif
 }
 
 MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_tls13_check_psk_key_exchange( mbedtls_ssl_context *ssl )
 {
-#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED)
+#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ENABLED)
     return( mbedtls_ssl_conf_tls13_psk_enabled( ssl ) &&
             mbedtls_ssl_tls13_psk_enabled( ssl ) &&
             ssl_tls13_client_hello_has_exts_for_psk_key_exchange( ssl ) );
@@ -992,7 +1001,7 @@
 MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_tls13_check_psk_ephemeral_key_exchange( mbedtls_ssl_context *ssl )
 {
-#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED)
+#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL_ENABLED)
     return( mbedtls_ssl_conf_tls13_psk_ephemeral_enabled( ssl ) &&
             mbedtls_ssl_tls13_psk_ephemeral_enabled( ssl ) &&
             ssl_tls13_client_hello_has_exts_for_psk_ephemeral_key_exchange( ssl ) );