diff --git a/config.h.in b/config.h.in

index 4ecaa8f..2f65ccc 100644

--- a/config.h.in

+++ b/config.h.in

@@ -600,7 +600,7 @@ int sigwait(const unsigned int *set, int *sig);

 #undef PREFER_GOSTASN1

 /* The size of `void *', as computed by sizeof. */

-#undef SIZEOF_VOID_P

+/* #undef SIZEOF_VOID_P */

 /* Define to 1 if you have the ANSI C header files. */

 #undef STDC_HEADERS

diff --git a/isc-config.sh.in b/isc-config.sh.in

index a8a0a89..b5e94ed 100644

--- a/isc-config.sh.in

+++ b/isc-config.sh.in

@@ -13,7 +13,18 @@ prefix=@prefix@

 exec_prefix=@exec_prefix@

 exec_prefix_set=

 includedir=@includedir@

-libdir=@libdir@

+arch=$(uname -m)

+

+case $arch in

+	x86_64 | amd64 | sparc64 | s390x | ppc64)

+		libdir=/usr/lib64

+		sec_libdir=/usr/lib

+		;;

+	* )

+		libdir=/usr/lib

+		sec_libdir=/usr/lib64

+		;;

+esac

 usage()

 {

@@ -132,6 +143,16 @@ if test x"$echo_libs" = x"true"; then

 	if test x"${exec_prefix_set}" = x"true"; then

 		libs="-L${exec_prefix}/lib"

 	else

+		if [ ! -x $libdir/libisc.so ] ; then

+			if [ ! -x $sec_libdir/libisc.so ] ; then

+				echo "Error: ISC libs not found in $libdir"

+				if [ -d $sec_libdir ] ; then

+					echo "Error: ISC libs not found in $sec_libdir"

+				fi

+				exit 1

+			fi

+			libdir=$sec_libdir

+		fi

 		libs="-L${libdir}"

 	fi

 	if test x"$libirs" = x"true" ; then