diff --git a/programs/ssl/ssl_server2.c b/programs/ssl/ssl_server2.c
index 390450b..7982ae9 100644
--- a/programs/ssl/ssl_server2.c
+++ b/programs/ssl/ssl_server2.c
@@ -56,6 +56,7 @@
 #include "mbedtls/x509.h"
 #include "mbedtls/error.h"
 #include "mbedtls/debug.h"
+#include "mbedtls/timing.h"
 
 #include <stdio.h>
 #include <stdlib.h>