diff --git a/src/netif/ppp/pppos.c b/src/netif/ppp/pppos.c
index 4ebd2baf..04481046 100644
--- a/src/netif/ppp/pppos.c
+++ b/src/netif/ppp/pppos.c
@@ -47,6 +47,7 @@
 #include "netif/ppp/ppp_impl.h"
 #include "netif/ppp/pppos.h"
 #include "netif/ppp/magic.h"
+#include "netif/ppp/vj.h"
 
 /* callbacks called from PPP core */
 static void pppos_link_command_callback(void *pcb, u8_t command);