diff --git a/nfq/darkmagic.c b/nfq/darkmagic.c
index 19143a0..cb6115b 100644
--- a/nfq/darkmagic.c
+++ b/nfq/darkmagic.c
@@ -959,7 +959,7 @@ void tcp_rewrite_winsize(struct tcphdr *tcp, uint16_t winsize, uint8_t scale_fac
 
 static HANDLE w_filter = NULL;
 static OVERLAPPED ovl = { .hEvent = NULL };
-DWORD w_win32_error=0;
+uint32_t w_win32_error=0;
 
 static HANDLE windivert_init_filter(const char *filter, UINT64 flags)
 {
@@ -1082,7 +1082,9 @@ bool windivert_recv(uint8_t *packet, size_t *len, WINDIVERT_ADDRESS *wa)
 
 static bool windivert_send_filter(HANDLE hFilter, const uint8_t *packet, size_t len, const WINDIVERT_ADDRESS *wa)
 {
-	return WinDivertSend(hFilter,packet,(UINT)len,NULL,wa);
+	bool b = WinDivertSend(hFilter,packet,(UINT)len,NULL,wa);
+	w_win32_error = GetLastError();
+	return b;
 }
 bool windivert_send(const uint8_t *packet, size_t len, const WINDIVERT_ADDRESS *wa)
 {
diff --git a/nfq/darkmagic.h b/nfq/darkmagic.h
index ba09180..8108185 100644
--- a/nfq/darkmagic.h
+++ b/nfq/darkmagic.h
@@ -149,7 +149,7 @@ uint8_t tcp_find_scale_factor(const struct tcphdr *tcp);
 bool tcp_has_fastopen(const struct tcphdr *tcp);
 
 #ifdef __CYGWIN__
-extern DWORD w_win32_error;
+extern uint32_t w_win32_error;
 
 bool windivert_init(const char *filter);
 bool windivert_recv(uint8_t *packet, size_t *len, WINDIVERT_ADDRESS *wa);