diff --git a/lib/socket.c b/lib/socket.c
index fb64261..7b93fec 100644
--- a/lib/socket.c
+++ b/lib/socket.c
@@ -140,7 +140,7 @@ static int set_tcp_sockopt(int sockfd, int optname, int value)
 {
 	int level;
 
-	#if defined(__FreeBSD__) || defined(__sun) || (defined(__APPLE__) && defined(__MACH__))
+	#ifndef SOL_TCP
 	struct protoent *buf;
 
 	if ((buf = getprotobyname("tcp")) != NULL)