diff -ur GTorrentViewer-0.2b.orig/configure GTorrentViewer-0.2b/configure
--- GTorrentViewer-0.2b.orig/configure	2022-11-25 10:59:57.070030177 +0100
+++ GTorrentViewer-0.2b/configure	2022-11-25 11:01:15.931236749 +0100
@@ -3486,8 +3486,8 @@
   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