diff -Nru a2ps-4.15.6_copy/liba2ps/jobs.c a2ps-4.15.6/liba2ps/jobs.c
--- a2ps-4.15.6_copy/liba2ps/jobs.c	2025-02-28 16:36:18.778073534 +0800
+++ a2ps-4.15.6/liba2ps/jobs.c	2025-02-28 16:53:11.859779055 +0800
@@ -119,6 +119,7 @@
   setlocale (LC_TIME, "");
   setlocale (LC_MESSAGES, "");
   setlocale (LC_CTYPE, "");
+  setlocale (LC_PAPER, "");
 
   bindtextdomain (PACKAGE, LOCALEDIR);
   bindtextdomain (PACKAGE "-gnulib", LOCALEDIR);
diff -Nru a2ps-4.15.6_copy/liba2ps/options.c a2ps-4.15.6/liba2ps/options.c
--- a2ps-4.15.6_copy/liba2ps/options.c	2025-02-28 16:36:18.779073539 +0800
+++ a2ps-4.15.6/liba2ps/options.c	2025-02-28 16:57:44.545312403 +0800
@@ -40,6 +40,8 @@
 #include "argv.h"
 #include "quotearg.h"
 #include "filalign.h"
+#include <locale.h>
+#include <langinfo.h>
 #include "version-etc.h"
 
 #define MAN_LINES               66	/* no lines for a man */
@@ -268,6 +270,8 @@
   struct opt_optarg *opt_optarg = NULL;
   int res;
 
+  unsigned int paper_height=0;
+
   /* Reset optind so that getopt is reinitialized. */
   optind = 0;
 
@@ -515,7 +519,14 @@
 	break;
 
       case 'M':                 		/* select a medium */
-	xstrcpy (job->medium_request, optarg);
+          if(strcasecmp("_glibc",optarg)==0){
+              paper_height = ((union { char *string; unsigned int word; })nl_langinfo(_NL_PAPER_HEIGHT)).word;
+              if(paper_height==279) /* US Letter */
+                  strcpy(optarg,"letter");
+              else /* Everyone else */
+                  strcpy(optarg,"a4");
+          }
+          xstrcpy (job->medium_request, optarg);
 	break;
 
       case 'n':				/* n copies */
diff -Nru a2ps-4.15.6_copy/src/main.c a2ps-4.15.6/src/main.c
--- a2ps-4.15.6_copy/src/main.c	2025-02-28 16:36:18.810073714 +0800
+++ a2ps-4.15.6/src/main.c	2025-02-28 16:58:34.738593097 +0800
@@ -926,6 +926,7 @@
   setlocale (LC_TIME, "");
   setlocale (LC_MESSAGES, "");
   setlocale (LC_CTYPE, "");
+  setlocale (LC_PAPER, "");
 
   bindtextdomain (PACKAGE, LOCALEDIR);
   bindtextdomain (PACKAGE "-gnulib", LOCALEDIR);