diff --git a/src/core/memp.c b/src/core/memp.c
index 3ef99af8..1fa42429 100644
--- a/src/core/memp.c
+++ b/src/core/memp.c
@@ -64,6 +64,8 @@
 #include "lwip/priv/tcpip_priv.h"
 #include "lwip/netifapi.h"
 
+#include "netif/ppp/ppp_opts.h"
+
 #include <string.h>
 
 #define LWIP_MEMPOOL(name,num,size,desc) LWIP_MEMPOOL_DECLARE(name,num,size,desc)
diff --git a/src/netif/ethernet.c b/src/netif/ethernet.c
index 6d843913..dc79f3b9 100644
--- a/src/netif/ethernet.c
+++ b/src/netif/ethernet.c
@@ -48,6 +48,7 @@
 
 #include <string.h>
 
+#include "netif/ppp/ppp_opts.h"
 #if PPPOE_SUPPORT
 #include "netif/ppp/pppoe.h"
 #endif /* PPPOE_SUPPORT */