diff --git a/modules/upnp/upnp.cpp b/modules/upnp/upnp.cpp
index cff13251cee..8e4e833d45e 100644
--- a/modules/upnp/upnp.cpp
+++ b/modules/upnp/upnp.cpp
@@ -52,10 +52,12 @@ int UPNP::discover(int timeout, int ttl, const String &device_filter) {
 	int error = 0;
 	struct UPNPDev *devlist;
 
+	CharString cs = discover_multicast_if.utf8();
+	const char *m_if = cs.length() ? cs.get_data() : nullptr;
 	if (is_common_device(device_filter)) {
-		devlist = upnpDiscover(timeout, discover_multicast_if.utf8().get_data(), nullptr, discover_local_port, discover_ipv6, ttl, &error);
+		devlist = upnpDiscover(timeout, m_if, nullptr, discover_local_port, discover_ipv6, ttl, &error);
 	} else {
-		devlist = upnpDiscoverAll(timeout, discover_multicast_if.utf8().get_data(), nullptr, discover_local_port, discover_ipv6, ttl, &error);
+		devlist = upnpDiscoverAll(timeout, m_if, nullptr, discover_local_port, discover_ipv6, ttl, &error);
 	}
 
 	if (error != UPNPDISCOVER_SUCCESS) {
diff --git a/thirdparty/README.md b/thirdparty/README.md
index efeefedbddd..0eb227d0f96 100644
--- a/thirdparty/README.md
+++ b/thirdparty/README.md
@@ -364,7 +364,6 @@ Files extracted from upstream source:
 - All `*.c` and `*.h` files from `miniupnpc` to `thirdparty/miniupnpc/miniupnpc`
 - Remove `test*`, `minihttptestserver.c` and `wingenminiupnpcstrings.c`
 
-The patch `windows_fix.diff` is applied to `minissdpc.c` to fix an upstream issue.
 The only modified file is miniupnpcstrings.h, which was created for Godot
 (it is usually autogenerated by cmake).
 
diff --git a/thirdparty/miniupnpc/miniupnpc/minissdpc.c b/thirdparty/miniupnpc/miniupnpc/minissdpc.c
index 36244dedecc..a3b1283da59 100644
--- a/thirdparty/miniupnpc/miniupnpc/minissdpc.c
+++ b/thirdparty/miniupnpc/miniupnpc/minissdpc.c
@@ -683,7 +683,11 @@ ssdpDiscoverDevices(const char * const deviceTypes[],
 #endif
 		} else {
 			struct in_addr mc_if;
+#if defined(_WIN32) && (_WIN32_WINNT >= _WIN32_WINNT_VISTA)
+			InetPtonA(AF_INET, multicastif, &mc_if);
+#else
 			mc_if.s_addr = inet_addr(multicastif); /* ex: 192.168.x.x */
+#endif
 			if(mc_if.s_addr != INADDR_NONE)
 			{
 				((struct sockaddr_in *)&sockudp_r)->sin_addr.s_addr = mc_if.s_addr;
diff --git a/thirdparty/miniupnpc/windows_fix.diff b/thirdparty/miniupnpc/windows_fix.diff
deleted file mode 100644
index 460b596888e..00000000000
--- a/thirdparty/miniupnpc/windows_fix.diff
+++ /dev/null
@@ -1,16 +0,0 @@
-diff --git a/thirdparty/miniupnpc/miniupnpc/minissdpc.c b/thirdparty/miniupnpc/miniupnpc/minissdpc.c
-index 29f8110155..ea9af02e1f 100644
---- a/thirdparty/miniupnpc/miniupnpc/minissdpc.c
-+++ b/thirdparty/miniupnpc/miniupnpc/minissdpc.c
-@@ -683,11 +683,7 @@ ssdpDiscoverDevices(const char * const deviceTypes[],
- #endif
- 		} else {
- 			struct in_addr mc_if;
--#if defined(_WIN32) && (_WIN32_WINNT >= _WIN32_WINNT_VISTA)
--			InetPtonA(AF_INET, multicastif, &mc_if);
--#else
- 			mc_if.s_addr = inet_addr(multicastif); /* ex: 192.168.x.x */
--#endif
- 			if(mc_if.s_addr != INADDR_NONE)
- 			{
- 				((struct sockaddr_in *)&sockudp_r)->sin_addr.s_addr = mc_if.s_addr;