diff --git a/contrib/ports/win32/example_app/default_netif.c b/contrib/ports/win32/example_app/default_netif.c
index 89083c51..9af2ecca 100644
--- a/contrib/ports/win32/example_app/default_netif.c
+++ b/contrib/ports/win32/example_app/default_netif.c
@@ -34,6 +34,7 @@
 
 #include "lwip/netif.h"
 #include "lwip/ip_addr.h"
+#include "lwip/sys.h"
 #include "lwip/tcpip.h"
 #include "../pcapif.h"
 #include "examples/example_app/default_netif.h"