--- a/configure.in
+++ b/configure.in
@@ -21,7 +21,7 @@
 ### along with Octave; see the file COPYING.  If not, write to the Free
 ### Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 
-AC_REVISION($Revision: 1.70 $)
+AC_REVISION($Revision: 1.71 $)
 AC_PREREQ(2.0)
 AC_INIT(src/octave.cc)
 AC_CONFIG_HEADER(config.h kpathsea/c-auto.h)
@@ -29,9 +29,12 @@
 AC_DEFINE(OCTAVE_SOURCE, 1)
 
 AC_CANONICAL_HOST
-target_host_type=${host:=unknown}
-canonical_host_type=${host:=unknown}
-if test "$host" = "unknown"; then
+if test -z "$host"; then
+  host=unknown
+fi
+target_host_type=$host
+canonical_host_type=$host
+if test "$host" = unknown; then
   AC_MSG_WARN([configuring Octave for unknown system type
 ])
 fi
@@ -624,7 +627,13 @@
 ### Signal stuff.
 
 AC_TYPE_SIGNAL
-AC_SYS_SIGLIST_DECLARED
+AC_DECL_SYS_SIGLIST
+AC_MSG_CHECKING([for sys_siglist variable])
+AC_TRY_LINK([#include <stdio.h>],
+  [extern char *sys_siglist[]; printf ("%s\n", sys_siglist[1]);],
+  AC_MSG_RESULT(yes)
+  AC_DEFINE(HAVE_SYS_SIGLIST, 1),
+  AC_MSG_RESULT(no))
 
 ### Define VOID_SIGHANDLER for readline.