diff --git a/src/murmur/Server.cpp b/src/murmur/Server.cpp
index 9c6dd4af3..1c3ebb545 100644
--- a/src/murmur/Server.cpp
+++ b/src/murmur/Server.cpp
@@ -50,6 +50,13 @@ bool SslServer::hasDualStackSupport() {
 	bool result = false;
 #ifdef Q_OS_UNIX
 	int s = ::socket(AF_INET6, SOCK_STREAM, 0);
+	if (s != -1) {
+		const int ipv6only = 0;
+		if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, reinterpret_cast<const char*>(&ipv6only), sizeof(ipv6only)) == 0) {
+			result = true;
+		}
+		::close(s);
+	}
 #else
 	WSADATA wsaData;
 	WORD wVersionRequested = MAKEWORD(2, 2);
@@ -59,17 +66,11 @@ bool SslServer::hasDualStackSupport() {
 	}
 
 	SOCKET s = ::WSASocket(AF_INET6, SOCK_STREAM, IPPROTO_TCP, NULL, 0, WSA_FLAG_OVERLAPPED);
-#endif
-
-	if (s != -1) { // Equals INVALID_SOCKET
+	if (s != INVALID_SOCKET) {
 		const int ipv6only = 0;
 		if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, reinterpret_cast<const char*>(&ipv6only), sizeof(ipv6only)) == 0) {
 			result = true;
 		}
-#ifdef Q_OS_UNIX
-		::close(s);
-	}
-#else
 		closesocket(s);
 	}
 	WSACleanup();