diff --git a/src/apps/altcp_tls/altcp_tls_mbedtls.c b/src/apps/altcp_tls/altcp_tls_mbedtls.c
index e787ae28..ee3eee5c 100644
--- a/src/apps/altcp_tls/altcp_tls_mbedtls.c
+++ b/src/apps/altcp_tls/altcp_tls_mbedtls.c
@@ -3,6 +3,8 @@
  * Application layered TCP/TLS connection API (to be used from TCPIP thread)
  *
  * This file provides a TLS layer using mbedTLS
+ * 
+ * This version is currently compatible with the 2.x.x branch (current LTS).
  */
 
 /*