diff -Nurd libast-0.7.orig/configure libast-0.7/configure
--- libast-0.7.orig/configure	2006-01-23 13:20:35.000000000 -0500
+++ libast-0.7/configure	2025-01-19 18:41:00.000000000 -0500
@@ -3538,6 +3538,7 @@
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 #include <ctype.h>
+#include <stdlib.h>
 #if ((' ' & 0x0FF) == 0x020)
 # define ISLOWER(c) ('a' <= (c) && (c) <= 'z')
 # define TOUPPER(c) (ISLOWER(c) ? 'A' + ((c) - 'a') : (c))
@@ -23741,6 +23742,7 @@
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 #include <stdio.h>
+#include <stdlib.h>
 
 #ifndef HAVE_SNPRINTF
 #include "src/snprintf.c"
@@ -23824,6 +23826,7 @@
 /* end confdefs.h.  */
 #include <stdio.h>
 #include <stdarg.h>
+#include <stdlib.h>
 
 #ifndef HAVE_VSNPRINTF
 #include "src/snprintf.c"