diff --git a/ports/win32/pcapif.h b/ports/win32/pcapif.h
index 736fbc8..534d9d5 100644
--- a/ports/win32/pcapif.h
+++ b/ports/win32/pcapif.h
@@ -1,6 +1,10 @@
 #ifndef __PCAPIF_H__
 #define __PCAPIF_H__
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #include "lwip/err.h"
 
 /** Set to 1 to let rx use an own thread (only for NO_SYS==0).
@@ -21,4 +25,8 @@ void  pcapif_shutdown(struct netif *netif);
 void  pcapif_poll    (struct netif *netif);
 #endif /* !PCAPIF_RX_USE_THREAD */
 
+#ifdef __cplusplus
+}
 #endif
+
+#endif /* __PCAPIF_H__ */
diff --git a/ports/win32/pcapif_helper.h b/ports/win32/pcapif_helper.h
index 9fc69ff..abb2894 100644
--- a/ports/win32/pcapif_helper.h
+++ b/ports/win32/pcapif_helper.h
@@ -1,6 +1,9 @@
 #ifndef __PCAPIF_HELPER_H__
 #define __PCAPIF_HELPER_H__
 
+#ifdef __cplusplus
+extern "C" {
+#endif
 
 struct pcapifh_linkstate;
 
@@ -15,4 +18,8 @@ enum pcapifh_link_event pcapifh_linkstate_get(struct pcapifh_linkstate* state);
 void pcapifh_linkstate_close(struct pcapifh_linkstate* state);
 
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* __PCAPIF_HELPER_H__ */
\ No newline at end of file
diff --git a/ports/win32/test.c b/ports/win32/test.c
index b765071..3f26431 100644
--- a/ports/win32/test.c
+++ b/ports/win32/test.c
@@ -158,7 +158,7 @@ pppLinkStatusCallback(void *ctx, int errCode, void *arg)
 
   switch(errCode) {
     case PPPERR_NONE: {             /* No error. */
-      struct ppp_addrs *ppp_addrs = arg;
+      struct ppp_addrs *ppp_addrs = (struct ppp_addrs *)arg;
 
       printf("pppLinkStatusCallback: PPPERR_NONE\n");
       printf(" our_ipaddr=%s\n", ip_ntoa(&ppp_addrs->our_ipaddr));