diff --git a/include/mbedtls/ssl_internal.h b/include/mbedtls/ssl_internal.h
index 82beea5..daf3f6a 100644
--- a/include/mbedtls/ssl_internal.h
+++ b/include/mbedtls/ssl_internal.h
@@ -182,6 +182,12 @@
         : ( MBEDTLS_SSL_IN_CONTENT_LEN )                             \
         )
 
+/* Maximum size in bytes of list in sig-hash algorithm ext., RFC 5246 */
+#define MBEDTLS_SSL_MAX_SIG_HASH_ALG_LIST_LEN  65534
+
+/* Maximum size in bytes of list in supported elliptic curve ext., RFC 4492 */
+#define MBEDTLS_SSL_MAX_CURVE_LIST_LEN         65535
+
 /*
  * Check that we obey the standard's message size bounds
  */