diff --git a/miniupnpc/addr_is_reserved.c b/miniupnpc/addr_is_reserved.c
index 7e586d7..18c6424 100644
--- a/miniupnpc/addr_is_reserved.c
+++ b/miniupnpc/addr_is_reserved.c
@@ -56,7 +56,7 @@ int addr_is_reserved(const char * addr_str)
 	uint32_t addr_n, address;
 	size_t i;
 
-#if defined(_WIN32) && (!defined(_WIN32_WINNT_VISTA) || (_WIN32_WINNT < _WIN32_WINNT_VISTA))
+#if defined(_WIN32) && _WIN32_WINNT < 0x0600 // _WIN32_WINNT_VISTA
 	addr_n = inet_addr(addr_str);
 	if (addr_n == INADDR_NONE)
 		return 1;
diff --git a/miniupnpc/minissdpc.c b/miniupnpc/minissdpc.c
index 0ef7e12..cf8aad6 100644
--- a/miniupnpc/minissdpc.c
+++ b/miniupnpc/minissdpc.c
@@ -460,7 +460,7 @@ parseMSEARCHReply(const char * reply, int size,
 static int upnp_gettimeofday(struct timeval * tv)
 {
 #if defined(_WIN32)
-#if defined(_WIN32_WINNT_VISTA) && (_WIN32_WINNT >= _WIN32_WINNT_VISTA)
+#if _WIN32_WINNT >= 0x0600 // _WIN32_WINNT_VISTA
 	ULONGLONG ts = GetTickCount64();
 #else
 	DWORD ts = GetTickCount();
@@ -722,7 +722,7 @@ ssdpDiscoverDevices(const char * const deviceTypes[],
 		} else {
 			struct in_addr mc_if;
 #if defined(_WIN32)
-#if defined(_WIN32_WINNT_VISTA) && (_WIN32_WINNT >= _WIN32_WINNT_VISTA)
+#if _WIN32_WINNT >= 0x0600 // _WIN32_WINNT_VISTA
 			InetPtonA(AF_INET, multicastif, &mc_if);
 #else
 			mc_if.s_addr = inet_addr(multicastif); /* old Windows SDK do not support InetPtoA() */