diff -u old/configure.in new/configure.in
--- old/configure.in	2009-02-12 19:00:29.000000000 -0500
+++ new/configure.in	2009-02-12 19:04:47.000000000 -0500
@@ -31,6 +31,10 @@
 AC_C_INLINE
 AC_PROG_INSTALL
 AC_PATH_PROG(RM,rm)
+AC_PATH_PROGS(PREFERRED_SHELL,ksh bash sh,no)
+if test "x$PREFERRED_SHELL" = xno ; then
+	AC_MSG_ERROR(could not find an appropriate shell)
+fi
 
 test "${USRCFLAGS}" = "" -a "${GCC}" = "yes" && CFLAGS="-g -O2 -Wall"
 test "${USRCFLAGS}" = "" -a "${GCC}" != "yes" && CFLAGS="-g -O"
diff -u old/Makefile.in new/Makefile.in
--- old/Makefile.in	2009-02-12 19:00:29.000000000 -0500
+++ new/Makefile.in	2009-02-12 19:02:48.000000000 -0500
@@ -4,7 +4,7 @@
 LDFLAGS		= @LDFLAGS@
 LIBS		= @LIBS@
 EXE		= @EXEEXT@
-SHELL		= /bin/ksh
+SHELL		= @PREFERRED_SHELL@
 
 prefix		= @prefix@
 exec_prefix     = @exec_prefix@