diff --git a/miniupnpc/addr_is_reserved.c b/miniupnpc/addr_is_reserved.c
index 8fc9f0b..c4ca2e5 100644
--- a/miniupnpc/addr_is_reserved.c
+++ b/miniupnpc/addr_is_reserved.c
@@ -55,13 +55,17 @@ int addr_is_reserved(const char * addr_str)
 	uint32_t addr_n, address;
 	size_t i;
 
+#if defined(_WIN32) && (_WIN32_WINNT < _WIN32_WINNT_VISTA)
+	addr_n = inet_addr(addr_str);
+	if (addr_n == INADDR_NONE)
+		return 1;
+#else
 	/* was : addr_n = inet_addr(addr_str); */
 	if (inet_pton(AF_INET, addr_str, &addr_n) < 0) {
 		/* error */
-		return 0;
-	}
-	if (addr_n == INADDR_NONE)
 		return 1;
+	}
+#endif
 
 	address = ntohl(addr_n);
 
diff --git a/miniupnpc/minissdpc.c b/miniupnpc/minissdpc.c
index db8f4b3..048cd25 100644
--- a/miniupnpc/minissdpc.c
+++ b/miniupnpc/minissdpc.c
@@ -717,8 +717,12 @@ ssdpDiscoverDevices(const char * const deviceTypes[],
 #endif
 		} else {
 			struct in_addr mc_if;
-#if defined(_WIN32) && (_WIN32_WINNT >= _WIN32_WINNT_VISTA)
+#if defined(_WIN32)
+#if (_WIN32_WINNT >= _WIN32_WINNT_VISTA)
 			InetPtonA(AF_INET, multicastif, &mc_if);
+#else
+			mc_if.s_addr = inet_addr(multicastif); /* old Windows SDK do not support InetPtoA() */
+#endif
 #else
 			/* was : mc_if.s_addr = inet_addr(multicastif); */ /* ex: 192.168.x.x */
 			if (inet_pton(AF_INET, multicastif, &mc_if.s_addr) < 0) {