diff -rup a/configure b/configure
--- a/configure	2023-03-02 16:47:06.631784108 -0500
+++ b/configure	2023-03-02 17:05:12.237816689 -0500
@@ -4593,8 +4593,8 @@ main ()
   for (i = 0; i < 256; i++)
     if (XOR (islower (i), ISLOWER (i))
 	|| toupper (i) != TOUPPER (i))
-      exit(2);
-  exit (0);
+      return 2;
+  return 0;
 }
 _ACEOF
 rm -f conftest$ac_exeext