diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h
index 2569f59..c64b1b2 100644
--- a/include/mbedtls/ssl.h
+++ b/include/mbedtls/ssl.h
@@ -1149,6 +1149,7 @@
  *                 here, except if using an event-driven style.
  *
  * \note           See also the "DTLS tutorial" article in our knowledge base.
+ *                 https://tls.mbed.org/kb/how-to/dtls-tutorial
  */
 void mbedtls_ssl_set_timer_cb( mbedtls_ssl_context *ssl,
                                void *p_timer,