diff --git a/library/ssl_tls13_server.c b/library/ssl_tls13_server.c
index 0dcd7ed..437e836 100644
--- a/library/ssl_tls13_server.c
+++ b/library/ssl_tls13_server.c
@@ -23,6 +23,8 @@
 
 #if defined(MBEDTLS_SSL_SRV_C)
 
+#include "mbedtls/debug.h"
+
 #include "ssl_misc.h"
 
 int mbedtls_ssl_tls13_handshake_server_step( mbedtls_ssl_context *ssl )