diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h
index 2d7beb3..780aa62 100644
--- a/include/mbedtls/ssl.h
+++ b/include/mbedtls/ssl.h
@@ -139,6 +139,9 @@
 #define MBEDTLS_SSL_TRANSPORT_STREAM            0   /*!< TLS      */
 #define MBEDTLS_SSL_TRANSPORT_DATAGRAM          1   /*!< DTLS     */
 
+#define MBEDTLS_SSL_MAX_HOST_NAME               255 /*!< Maximum host name
+defined in RFC 1035 */
+
 /* RFC 6066 section 4, see also mfl_code_to_length in ssl_tls.c
  * NONE must be zero so that memset()ing structure to zero works */
 #define MBEDTLS_SSL_MAX_FRAG_LEN_NONE           0   /*!< don't use this extension   */