diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 138e1da..930613b 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -1008,12 +1008,14 @@
 static int ssl_populate_transform( mbedtls_ssl_transform *transform,
                                    int ciphersuite,
                                    const unsigned char master[48],
+#if defined(MBEDTLS_SSL_SOME_MODES_USE_MAC)
 #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
                                    int encrypt_then_mac,
-#endif
+#endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
 #if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
                                    int trunc_hmac,
-#endif
+#endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
+#endif /* MBEDTLS_SSL_SOME_MODES_USE_MAC */
 #if defined(MBEDTLS_ZLIB_SUPPORT)
                                    int compression,
 #endif
@@ -1784,12 +1786,14 @@
     ret = ssl_populate_transform( ssl->transform_negotiate,
                                   ssl->session_negotiate->ciphersuite,
                                   ssl->session_negotiate->master,
+#if defined(MBEDTLS_SSL_SOME_MODES_USE_MAC)
 #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
                                   ssl->session_negotiate->encrypt_then_mac,
-#endif
+#endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
 #if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
                                   ssl->session_negotiate->trunc_hmac,
-#endif
+#endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
+#endif /* MBEDTLS_SSL_SOME_MODES_USE_MAC */
 #if defined(MBEDTLS_ZLIB_SUPPORT)
                                   ssl->session_negotiate->compression,
 #endif