diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h
index dd546b8..492a324 100644
--- a/include/mbedtls/ssl.h
+++ b/include/mbedtls/ssl.h
@@ -1049,7 +1049,9 @@
 
     unsigned int endpoint : 1;      /*!< 0: client, 1: server               */
     unsigned int transport : 1;     /*!< stream (TLS) or datagram (DTLS)    */
+#if !defined(MBEDTLS_SSL_CONF_AUTHMODE)
     unsigned int authmode : 2;      /*!< MBEDTLS_SSL_VERIFY_XXX             */
+#endif /* !MBEDTLS_SSL_CONF_AUTHMODE */
     /* needed even with renego disabled for LEGACY_BREAK_HANDSHAKE          */
     unsigned int allow_legacy_renegotiation : 2 ; /*!< MBEDTLS_LEGACY_XXX   */
 #if defined(MBEDTLS_ARC4_C)