diff --git a/include/netinet/tcp.h b/include/netinet/tcp.h
index 94e54cf3..f0fc1259 100644
--- a/include/netinet/tcp.h
+++ b/include/netinet/tcp.h
@@ -18,9 +18,8 @@
 #define TCP_CONGESTION	 13
 #define TCP_MD5SIG	 14
 
-#define SOL_TCP 6
-
 #if defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
+#define SOL_TCP 6
 #include <sys/types.h>
 #include <sys/socket.h>
 #endif