diff --git a/ChangeLog b/ChangeLog
index f7aa6eb..7b06fab 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2006-04-19  Bruno Haible  <bruno@clisp.org>
+
+	Prepare for autoconf-2.60.
+	* general.m4 (CL_CC_WORKS): Include <stdlib.h>, for exit() declaration.
+	* longdouble.m4 (CL_LONGDOUBLE): Likewise.
+	* longlong.m4 (CL_LONGLONG): Likewise.
+	* times.m4 (CL_TIMES_CLOCK): Likewise.
+	Reported by Ralf Wildenhues <Ralf.Wildenhues@gmx.de>.
+
 2005-12-04  Bruno Haible  <bruno@clisp.org>
 
 	* src/integer/conv/cl_I_to_digits.cc (I_to_digits_noshrink): Set
diff --git a/m4/general.m4 b/m4/general.m4
index 0c550af..b9fa4ba 100644
--- a/m4/general.m4
+++ b/m4/general.m4
@@ -1,4 +1,4 @@
-dnl Copyright (C) 1993-2002 Free Software Foundation, Inc.
+dnl Copyright (C) 1993-2006 Free Software Foundation, Inc.
 dnl This file is free software, distributed under the terms of the GNU
 dnl General Public License.  As a special exception to the GNU General
 dnl Public License, this file may be distributed as part of a program
@@ -93,7 +93,10 @@ AC_DEFUN([CL_CC_WORKS],
 [AC_CACHE_CHECK(whether CC works at all, cl_cv_prog_cc_works, [
 AC_LANG_SAVE()
 AC_LANG_C()
-AC_TRY_RUN([int main() { exit(0); }],
+AC_TRY_RUN([
+#include <stdlib.h>
+int main() { exit(0); }
+],
 cl_cv_prog_cc_works=yes, cl_cv_prog_cc_works=no,
 AC_TRY_LINK([], [], cl_cv_prog_cc_works=yes, cl_cv_prog_cc_works=no))
 AC_LANG_RESTORE()
diff --git a/m4/longdouble.m4 b/m4/longdouble.m4
index 069de22..70b08e4 100644
--- a/m4/longdouble.m4
+++ b/m4/longdouble.m4
@@ -1,4 +1,4 @@
-dnl Copyright (C) 1993-2005 Free Software Foundation, Inc.
+dnl Copyright (C) 1993-2006 Free Software Foundation, Inc.
 dnl This file is free software, distributed under the terms of the GNU
 dnl General Public License.  As a special exception to the GNU General
 dnl Public License, this file may be distributed as part of a program
@@ -11,8 +11,11 @@ AC_PREREQ(2.13)
 
 AC_DEFUN([CL_LONGDOUBLE],
 [AC_CACHE_CHECK(for long double type, cl_cv_c_longdouble, [
-AC_TRY_RUN([int main()
-{ long double x = 2.7182818284590452354L; x = x*x; exit (x==0.0L); }],
+AC_TRY_RUN([
+#include <stdlib.h>
+int main()
+{ long double x = 2.7182818284590452354L; x = x*x; exit (x==0.0L); }
+],
 cl_cv_c_longdouble=yes, cl_cv_c_longdouble=no, [
 dnl When cross-compiling, use the test from gnulib.
 AC_TRY_COMPILE([
diff --git a/m4/longlong.m4 b/m4/longlong.m4
index e3bdb97..78fae88 100644
--- a/m4/longlong.m4
+++ b/m4/longlong.m4
@@ -1,5 +1,5 @@
 dnl -*- Autoconf -*-
-dnl Copyright (C) 1993-2005 Free Software Foundation, Inc.
+dnl Copyright (C) 1993-2006 Free Software Foundation, Inc.
 dnl This file is free software, distributed under the terms of the GNU
 dnl General Public License.  As a special exception to the GNU General
 dnl Public License, this file may be distributed as part of a program
@@ -12,7 +12,9 @@ AC_PREREQ(2.57)
 
 AC_DEFUN([CL_LONGLONG],
 [AC_CACHE_CHECK(for long long type, cl_cv_c_longlong, [
-AC_TRY_RUN([int main()
+AC_TRY_RUN([
+#include <stdlib.h>
+int main()
 {
 /* long longs don't work right with gcc-2.7.2 on m68k */
 /* long longs don't work right with gcc-2.7.2 on rs6000: avcall/tests.c gets
diff --git a/m4/times.m4 b/m4/times.m4
index c03b548..d0d2b0e 100644
--- a/m4/times.m4
+++ b/m4/times.m4
@@ -1,5 +1,5 @@
 dnl -*- Autoconf -*-
-dnl Copyright (C) 1993-2003 Free Software Foundation, Inc.
+dnl Copyright (C) 1993-2006 Free Software Foundation, Inc.
 dnl This file is free software, distributed under the terms of the GNU
 dnl General Public License.  As a special exception to the GNU General
 dnl Public License, this file may be distributed as part of a program
@@ -17,6 +17,7 @@ AC_CHECK_FUNC(times, , no_times=1)dnl
 if test -z "$no_times"; then
 AC_CACHE_CHECK(for times return value, cl_cv_func_times_return, [
 AC_TRY_RUN([
+#include <stdlib.h> /* needed for exit() */
 #include <sys/types.h>
 #include <time.h> /* needed for CLK_TCK */
 #ifndef CLK_TCK