diff -up openexr_ctl-1.0.1/configure.conf_gcc43 openexr_ctl-1.0.1/configure
--- openexr_ctl-1.0.1/configure.conf_gcc43	2008-01-09 17:08:57.000000000 +0100
+++ openexr_ctl-1.0.1/configure	2008-01-09 17:10:25.000000000 +0100
@@ -20851,6 +20851,7 @@ cat >>conftest.$ac_ext <<_ACEOF
 
 #include <CtlSimdInterpreter.h>
 #include <Iex.h>
+#include <cstdlib>
 
 int
 main ()
diff -up openexr_ctl-1.0.1/configure.ac.conf_gcc43 openexr_ctl-1.0.1/configure.ac
--- openexr_ctl-1.0.1/configure.ac.conf_gcc43	2008-01-09 17:11:25.000000000 +0100
+++ openexr_ctl-1.0.1/configure.ac	2008-01-09 17:12:17.000000000 +0100
@@ -108,6 +108,7 @@ AM_COMPILELINKRUN(
    [$CTL_LIBS],[[
 #include <CtlSimdInterpreter.h>
 #include <Iex.h>
+#include <cstdlib>
 ]],
    [[Ctl::SimdInterpreter interp; interp.setMaxInstCount(10);]],
    AC_MSG_RESULT([The ctl test program succeeded.]),