diff --git a/library/ssl_misc.h b/library/ssl_misc.h
index 3ac81a3..f20897d 100644
--- a/library/ssl_misc.h
+++ b/library/ssl_misc.h
@@ -2200,6 +2200,7 @@
     }
     return( 1 );
 }
+
 #endif /* MBEDTLS_SSL_PROTO_TLS1_3 */
 
 #if defined(MBEDTLS_SSL_PROTO_TLS1_2)
@@ -2493,4 +2494,10 @@
     unsigned char *buf, unsigned char *end );
 #endif /* MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED */
 
+#if defined(MBEDTLS_SSL_PROTO_TLS1_3) && \
+    defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
+int mbedtls_ssl_session_set_hostname( mbedtls_ssl_session *session,
+                                      const char *hostname );
+#endif
+
 #endif /* ssl_misc.h */