diff --git a/Quake/net_defs.h b/Quake/net_defs.h
index c95eede5..a57f2eb4 100644
--- a/Quake/net_defs.h
+++ b/Quake/net_defs.h
@@ -24,6 +24,8 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 	net_defs.h
 	functions and data private to the network layer
 
+	net_sys.h and its dependencies must be included
+	before net_defs.h.
 */
 
 #ifndef __NET_DEFS_H
@@ -31,7 +33,12 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 
 struct qsockaddr
 {
+#if defined(HAVE_SA_LEN)
+	unsigned char qsa_len;
+	unsigned char qsa_family;
+#else
 	short qsa_family;
+#endif	/* BSD, sockaddr */
 	unsigned char qsa_data[14];
 };
 
diff --git a/Quake/net_sys.h b/Quake/net_sys.h
index ec696c03..9b3dfa85 100644
--- a/Quake/net_sys.h
+++ b/Quake/net_sys.h
@@ -29,6 +29,8 @@
    limited SDL_net functionality. */
 #undef	BAN_TEST
 
+#undef	HAVE_SA_LEN
+
 #define	sys_socket_t	int
 #define	INVALID_SOCKET	(-1)
 #define	SOCKET_ERROR	(-1)
@@ -53,11 +55,26 @@
 #ifndef __NET_SYS_H__
 #define __NET_SYS_H__
 
+#undef	HAVE_SA_LEN
+
 #include <sys/types.h>
 #include <errno.h>
 #include <stddef.h>
 #include <limits.h>
 
+#if defined(__FreeBSD__) || defined(__DragonFly__)	|| \
+    defined(__OpenBSD__) || defined(__NetBSD__)		|| \
+    defined(__MACOSX__)
+/* struct sockaddr has unsigned char sa_len as the first member in BSD
+ * in BSD variants and the family member is also an unsigned char instead
+ * of (unsigned) short. This should matter only when PLATFORM_UNIX is
+ * defined. */
+#define	HAVE_SA_LEN	1
+#define	SA_FAM_OFFSET	1
+#else
+#define	SA_FAM_OFFSET	0
+#endif	/* BSD, sockaddr */
+
 /* unix includes and compatibility macros */
 #if defined(PLATFORM_UNIX) || defined(PLATFORM_AMIGA)
 
@@ -95,6 +112,9 @@ typedef int	socklen_t;
 
 #define	socketerror(x)	strerror((x))
 
+/* Verify that we defined HAVE_SA_LEN correctly: */
+typedef char _check_sockaddr[2 * (offsetof(struct sockaddr, sa_family) == SA_FAM_OFFSET) - 1];
+
 #endif	/* end of unix stuff */
 
 
@@ -126,6 +146,9 @@ typedef SOCKET	sys_socket_t;
 /* must #include "wsaerror.h" for this : */
 #define	socketerror(x)	__WSAE_StrError((x))
 
+/* Verify that we defined HAVE_SA_LEN correctly: */
+typedef char _check_sockaddr[2 * (offsetof(struct sockaddr, sa_family) == SA_FAM_OFFSET) - 1];
+
 #endif	/* end of windows stuff */