diff --git a/src/include/netif/ppp/pppos.h b/src/include/netif/ppp/pppos.h
index b7d56526..57fca08e 100644
--- a/src/include/netif/ppp/pppos.h
+++ b/src/include/netif/ppp/pppos.h
@@ -61,9 +61,9 @@ ppp_pcb *ppp_over_serial_create(struct netif *pppif, sio_fd_t fd,
 void pppos_input(ppp_pcb *ppp, u_char* data, int len);
 
 
-void pppos_vjc_config(ppp_pcb *ppp, int vjcomp, int cidcomp, int maxcid);
-int pppos_vjc_comp(ppp_pcb *ppp, struct pbuf *pb);
-int pppos_vjc_uncomp(ppp_pcb *ppp, struct pbuf *pb);
+void pppos_vjc_config(pppos_pcb *pppos, int vjcomp, int cidcomp, int maxcid);
+int pppos_vjc_comp(pppos_pcb *pppos, struct pbuf *pb);
+int pppos_vjc_uncomp(pppos_pcb *pppos, struct pbuf *pb);
 
 #endif /* PPPOS_H */
 #endif /* PPP_SUPPORT && PPPOL2TP_SUPPORT */
diff --git a/src/netif/ppp/ppp.c b/src/netif/ppp/ppp.c
index 0fec0774..2a446a65 100644
--- a/src/netif/ppp/ppp.c
+++ b/src/netif/ppp/ppp.c
@@ -91,6 +91,9 @@
 #include "lwip/sio.h"
 #include "lwip/sys.h"
 #include "lwip/ip.h" /* for ip_input() */
+#if PPP_IPV6_SUPPORT
+#include "lwip/ip6.h" /* for ip6_input() */
+#endif /* PPP_IPV6_SUPPORT */
 
 #include "netif/ppp/ppp_impl.h"
 #include "netif/ppp/pppos.h"
@@ -582,13 +585,15 @@ void ppp_input(ppp_pcb *pcb, struct pbuf *pb) {
 
 #if VJ_SUPPORT
     case PPP_VJC_COMP:      /* VJ compressed TCP */
-      if (pppos_vjc_comp(pcb, pb) >= 0) {
+      /* VJ is only enabled on PPPoS interfaces */
+      if (pcb->vj_enabled && pppos_vjc_comp((pppos_pcb*)pcb->link_ctx_cb, pb) >= 0) {
         return;
       }
       break;
 
     case PPP_VJC_UNCOMP:    /* VJ uncompressed TCP */
-      if (pppos_vjc_uncomp(pcb, pb) >= 0) {
+      /* VJ is only enabled on PPPoS interfaces */
+      if (pcb->vj_enabled && pppos_vjc_uncomp((pppos_pcb*)pcb->link_ctx_cb, pb) >= 0) {
         return;
       }
       break;
@@ -1185,7 +1190,7 @@ int cifproxyarp(ppp_pcb *pcb, u32_t his_adr) {
  */
 int sifvjcomp(ppp_pcb *pcb, int vjcomp, int cidcomp, int maxcid) {
 #if VJ_SUPPORT
-  pppos_vjc_config(pcb, vjcomp, cidcomp, maxcid);
+  pppos_vjc_config((pppos_pcb*)pcb->link_ctx_cb, vjcomp, cidcomp, maxcid);
 #else /* VJ_SUPPORT */
   LWIP_UNUSED_ARG(pcb);
   LWIP_UNUSED_ARG(vjcomp);
diff --git a/src/netif/ppp/pppos.c b/src/netif/ppp/pppos.c
index 116d2243..8c5715fe 100644
--- a/src/netif/ppp/pppos.c
+++ b/src/netif/ppp/pppos.c
@@ -43,6 +43,7 @@
 #include "lwip/tcpip.h"
 #include "lwip/api.h"
 #include "lwip/sio.h"
+#include "lwip/ip.h" /* for ip_input() */
 
 #include "netif/ppp/ppp_impl.h"
 #include "netif/ppp/pppos.h"
@@ -744,32 +745,29 @@ drop:
 
 #if VJ_SUPPORT
 void
-pppos_vjc_config(ppp_pcb *ppp, int vjcomp, int cidcomp, int maxcid)
+pppos_vjc_config(pppos_pcb *pppos, int vjcomp, int cidcomp, int maxcid)
 {
-  pppos_pcb *pppos = (pppos_pcb *)ppp->link_ctx_cb;
+  ppp_pcb *ppp;
+
   if (!pppos_exist(pppos)) {
     return;
   }
+
+  ppp = pppos->ppp;
   ppp->vj_enabled = vjcomp;
   pppos->vj_comp.compressSlot = cidcomp;
   pppos->vj_comp.maxSlotIndex = maxcid;
-  PPPDEBUG(LOG_INFO, ("pppos_vjc_config: VJ compress enable=%d slot=%d max slot=%d\n",
-            vjcomp, cidcomp, maxcid));
+  PPPDEBUG(LOG_INFO, ("pppos_vjc_config[%d]: VJ compress enable=%d slot=%d max slot=%d\n",
+            ppp->num, vjcomp, cidcomp, maxcid));
 }
 
 int
-pppos_vjc_comp(ppp_pcb *ppp, struct pbuf *pb)
+pppos_vjc_comp(pppos_pcb *pppos, struct pbuf *pb)
 {
-  pppos_pcb *pppos;
+  ppp_pcb *ppp = pppos->ppp;
   int ret;
   PPPDEBUG(LOG_INFO, ("pppos_vjc_comp[%d]: vj_comp in pbuf len=%d\n", ppp->num, pb->len));
 
-  /* VJ is only enabled on PPPoS interfaces */
-  if (!ppp->vj_enabled) {
-    goto drop;
-  }
-  pppos = (pppos_pcb *)ppp->link_ctx_cb;
-
   /*
    * Clip off the VJ header and prepend the rebuilt TCP/IP header and
    * pass the result to IP.
@@ -780,25 +778,18 @@ pppos_vjc_comp(ppp_pcb *ppp, struct pbuf *pb)
     return ret;
   }
 
-drop:
   /* Something's wrong so drop it. */
   PPPDEBUG(LOG_WARNING, ("pppos_vjc_comp[%d]: Dropping VJ compressed\n", ppp->num));
   return -1;
 }
 
 int
-pppos_vjc_uncomp(ppp_pcb *ppp, struct pbuf *pb)
+pppos_vjc_uncomp(pppos_pcb *pppos, struct pbuf *pb)
 {
-  pppos_pcb *pppos;
+  ppp_pcb *ppp = pppos->ppp;
   int ret;
   PPPDEBUG(LOG_INFO, ("pppos_vjc_uncomp[%d]: vj_un in pbuf len=%d\n", ppp->num, pb->len));
 
-  /* VJ is only enabled on PPPoS interfaces */
-  if (!ppp->vj_enabled) {
-    goto drop;
-  }
-  pppos = (pppos_pcb *)ppp->link_ctx_cb;
-
   /*
    * Process the TCP/IP header for VJ header compression and then pass
    * the packet to IP.
@@ -809,7 +800,6 @@ pppos_vjc_uncomp(ppp_pcb *ppp, struct pbuf *pb)
     return ret;
   }
 
-drop:
   /* Something's wrong so drop it. */
   PPPDEBUG(LOG_WARNING, ("pppos_vjc_uncomp[%d]: Dropping VJ uncompressed\n", ppp->num));
   return -1;