diff --git a/MANIFEST b/MANIFEST
index 23e55126f355..7759b182f086 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -5917,6 +5917,7 @@ regen/genpacksizetables.pl		Generate the size tables for pack/unpack
 regen/HeaderParser.pm			Module used to parse header files
 regen/keywords.pl			Program to write keywords.h
 regen/lib_cleanup.pl			Generate lib/.gitignore from MANIFEST
+regen/locale.pl				Program to write locale_table.h
 regen/mg_vtable.pl			generate mg_vtable.h
 regen/miniperlmain.pl			generate miniperlmain.c
 regen/mk_invlists.pl			Generates charclass_invlists.h
diff --git a/Makefile.SH b/Makefile.SH
index 0833a1b9971c..d5206fdc33af 100755
--- a/Makefile.SH
+++ b/Makefile.SH
@@ -1262,6 +1262,7 @@ CHMOD_W = chmod +w
 #	regcomp.pl:	regnodes.h
 #	warnings.pl:	warnings.h lib/warnings.pm
 #	feature.pl:	feature.h lib/feature.pm
+#	locale.pl:	locale_table.h
 # The correct versions should be already supplied with the perl kit,
 # in case you don't have perl available.
 # To force them to be regenerated, run
diff --git a/locale_table.h b/locale_table.h
index 326009956bb7..7c50b69119ce 100644
--- a/locale_table.h
+++ b/locale_table.h
@@ -1,11 +1,18 @@
-/*    locale_entry.h
+/* -*- mode: C; buffer-read-only: t -*-
  *
- *    Copyright (C) 2023 by Larry Wall and others
+ *    locale_table.h
+ *
+ *    Copyright (C) 2023, 2024 by Larry Wall and others
  *
  *    You may distribute under the terms of either the GNU General Public
  *    License or the Artistic License, as specified in the README file.
  *
- * This defines a macro for each individual locale category used on the this
+ * !!!!!!!   DO NOT EDIT THIS FILE   !!!!!!!
+ * This file is built by regen/locale.pl from data in regen/locale.pl.
+ * Any changes made here will be lost!
+ */
+
+/* This defines a macro for each individual locale category used on the this
  * system.  (The congomerate category LC_ALL is not included.)  This
  * file will be #included as the interior of various parallel arrays and in
  * other constructs; each usage will re-#define the macro to generate its
@@ -203,3 +210,5 @@
 #    define USE_LOCALE_TOD
 #  endif
 #endif
+
+/* ex: set ro ft=c: */
diff --git a/regen.pl b/regen.pl
index 5ea59e0f5ca7..31299b90c65c 100644
--- a/regen.pl
+++ b/regen.pl
@@ -33,3 +33,4 @@
 scope_types.pl
 tidy_embed.pl
 warnings.pl
+locale.pl
diff --git a/regen/locale.pl b/regen/locale.pl
new file mode 100644
index 000000000000..70676dac7693
--- /dev/null
+++ b/regen/locale.pl
@@ -0,0 +1,123 @@
+#!/usr/bin/perl -w
+#
+# Regenerate (overwriting only if changed):
+#
+#    locale_table.h
+#
+# Also accepts the standard regen_lib -q and -v args.
+#
+# This script is normally invoked from regen.pl.
+
+BEGIN {
+    require './regen/regen_lib.pl';
+}
+
+use strict;
+use warnings;
+
+sub open_print_header {
+    my ($file, $quote) = @_;
+    return open_new($file, '>',
+                    { by => 'regen/locale.pl',
+                      from => 'data in regen/locale.pl',
+                      file => $file, style => '*',
+                      copyright => [2023..2024],
+                      quote => $quote });
+}
+
+my $l = open_print_header('locale_table.h');
+print $l <<EOF;
+/* This defines a macro for each individual locale category used on the this
+ * system.  (The congomerate category LC_ALL is not included.)  This
+ * file will be #included as the interior of various parallel arrays and in
+ * other constructs; each usage will re-#define the macro to generate its
+ * appropriate data.
+ *
+ * This guarantees the arrays will be parallel, and populated in the order
+ * given here.  That order is mostly arbitrary.  LC_CTYPE is first because when
+ * we are setting multiple categories, CTYPE often needs to match the other(s),
+ * and the way the code is constructed, if we set the other category first, we
+ * might otherwise have to set CTYPE twice.
+ *
+ * Each entry takes the token giving the category name, and either the name of
+ * a function to call that does specialized set up for this category when it is
+ * changed into, or NULL if no such set up is needed
+ */
+
+EOF
+
+# It's not worth generalizing these further.
+my %comment = ( COLLATE => <<EOF
+
+        /* Perl outsources all its collation efforts to the libc strxfrm(), so
+         * if it isn't available on the system, default "C" locale collation
+         * gets used */
+EOF
+              );
+my %extra_conditional = (
+                          COLLATE => " || ! defined(HAS_STRXFRM)",
+                        );
+
+
+while (<DATA>) { # Read in the categories
+    chomp;
+    my ($name, $function) = split /\s*\|\s*/, $_;
+
+    my $macro_arg = $function ? $function : "NULL";
+    my $macro_with_func = "PERL_LOCALE_TABLE_ENTRY($name, $macro_arg)";
+    my $macro_sans_func = "PERL_LOCALE_TABLE_ENTRY($name, NULL)";
+    my ($common_macro, $macro_if_name, $macro_unless_name);
+    if ($macro_with_func eq $macro_sans_func) {
+        $common_macro = $macro_with_func;
+        $macro_if_name = "";
+        $macro_unless_name = "";
+    }
+    else {
+        $common_macro = "";
+        $macro_if_name = $macro_with_func;
+        $macro_unless_name = $macro_sans_func;
+    }
+
+    print $l "#ifdef LC_${name}\n";
+    print $l $comment{$name} if defined $comment{$name};
+    print $l "\n    $common_macro\n\n" if $common_macro;
+
+    my $extra = "";
+    $extra = $extra_conditional{$name} if defined $extra_conditional{$name};
+    print $l "#  if defined(NO_LOCALE) || defined(NO_LOCALE_${name})$extra\n";
+
+    print $l "\n    $macro_unless_name\n\n" if $macro_unless_name;
+    print $l <<~EOF;
+        #    define HAS_IGNORED_LOCALE_CATEGORIES_
+        #    define LC_${name}_AVAIL_  0
+        #  else
+        EOF
+    print $l "\n    $macro_if_name\n\n" if $macro_if_name;
+    print $l <<~EOF;
+        #    define LC_${name}_AVAIL_  1
+        #    define USE_LOCALE_${name}
+        #  endif
+        #endif
+        EOF
+}
+
+close DATA;
+
+read_only_bottom_close_and_rename($l);
+
+# category | update function
+__DATA__
+CTYPE   | S_new_ctype
+NUMERIC | S_new_numeric
+COLLATE | S_new_collate
+TIME
+MESSAGES
+MONETARY
+ADDRESS
+IDENTIFICATION
+MEASUREMENT
+PAPER
+TELEPHONE
+NAME
+SYNTAX
+TOD
diff --git a/t/porting/regen.t b/t/porting/regen.t
index f6eb24743b9b..e5c8bcad8470 100644
--- a/t/porting/regen.t
+++ b/t/porting/regen.t
@@ -27,7 +27,7 @@ if ( $Config{usecrosscompile} ) {
   skip_all( "Not all files are available during cross-compilation" );
 }
 
-my $tests = 27; # I can't see a clean way to calculate this automatically.
+my $tests = 28; # I can't see a clean way to calculate this automatically.
 
 my %skip = ("regen_perly.pl"    => [qw(perly.act perly.h perly.tab)],
             "regen/keywords.pl" => [qw(keywords.c keywords.h)],