Index: b/usr/src/lib/libresolv2/common/resolv/res_mkquery.c
===================================================================
--- a/usr/src/lib/libresolv2/common/resolv/res_mkquery.c
+++ b/usr/src/lib/libresolv2/common/resolv/res_mkquery.c
@@ -98,6 +98,13 @@ static const char rcsid[] = "$Id: res_mk
 #include <string.h>
 #include "port_after.h"
 
+/* from /usr/include/netinet/in.h.  */
+#if !defined(IN_SET_LOOPBACK_ADDR)
+#define IN_SET_LOOPBACK_ADDR(a) \
+        { (a)->sin_addr.s_addr  = htonl(INADDR_LOOPBACK); \
+        (a)->sin_family = AF_INET; }
+#endif
+
 /* Options.  Leave them on. */
 #define DEBUG