diff -aurN rxvt-unicode-6.3.orig/autoconf/configure.in rxvt-unicode-6.3/autoconf/configure.in
--- rxvt-unicode-6.3.orig/autoconf/configure.in	2006-01-04 06:16:42.000000000 +0100
+++ rxvt-unicode-6.3/autoconf/configure.in	2006-01-06 23:19:40.000000000 +0100
@@ -77,11 +77,11 @@
 AC_ISC_POSIX
 
 dnl# FreeBSD needs to link libxpg4
-AC_CHECK_FUNC(setlocale,     [], [AC_CHECK_LIB(xpg4,   setlocale,     [LIBS="$LIBS -lxpg4"])])
+AC_SEARCH_LIBS(setlocale, xpg4)
 
 dnl# solaris needs to link libnsl and socket
-AC_CHECK_FUNC(gethostbyname, [], [AC_CHECK_LIB(nsl,    gethostbyname, [LIBS="$LIBS -lnsl"])])
-AC_CHECK_FUNC(socket,        [], [AC_CHECK_LIB(socket, socket,        [LIBS="$LIBS -lsocket"])])
+AC_SEARCH_LIBS(nsl, gethostbyname)
+AC_SEARCH_LIBS(socket, socket)
 
 dnl# more solaris
 AC_CHECK_FUNC(sched_yield,   [], [AC_CHECK_LIB(rt,     sched_yield,   [LIBS="$LIBS -lrt"])])