diff --git a/MANIFEST b/MANIFEST
index fc5792f218c27..a6a91e68ee0f2 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -4157,6 +4157,7 @@ dist/ExtUtils-CBuilder/t/01-basic.t					tests for ExtUtils::CBuilder
 dist/ExtUtils-CBuilder/t/02-link.t					tests for ExtUtils::CBuilder
 dist/ExtUtils-CBuilder/t/03-cplusplus.t					tests for ExtUtils::CBuilder
 dist/ExtUtils-CBuilder/t/04-base.t					tests for ExtUtils::CBuilder
+dist/ExtUtils-ParseXS/author/mksnapshot.pl			Utility for detecting before/after changes to xsubpp output
 dist/ExtUtils-ParseXS/Changes					ExtUtils::ParseXS change log
 dist/ExtUtils-ParseXS/lib/ExtUtils/ParseXS.pm			converts Perl XS code into C code
 dist/ExtUtils-ParseXS/lib/ExtUtils/ParseXS.pod			ExtUtils::ParseXS documentation
diff --git a/Porting/exec-bit.txt b/Porting/exec-bit.txt
index f9abc7d605b3a..f18adb64efa66 100644
--- a/Porting/exec-bit.txt
+++ b/Porting/exec-bit.txt
@@ -20,6 +20,7 @@ dist/Devel-PPPort/devel/regenerate
 dist/Devel-PPPort/devel/scanprov
 dist/Devel-PPPort/devel/update_release_date.pl
 dist/Devel-PPPort/soak
+dist/ExtUtils-ParseXS/author/mksnapshot.pl
 dist/Thread-Queue/examples/callback.pl
 dist/Thread-Queue/examples/queue.pl
 installperl
diff --git a/dist/ExtUtils-ParseXS/author/mksnapshot.pl b/dist/ExtUtils-ParseXS/author/mksnapshot.pl
new file mode 100755
index 0000000000000..f4e490368f8e6
--- /dev/null
+++ b/dist/ExtUtils-ParseXS/author/mksnapshot.pl
@@ -0,0 +1,69 @@
+#!/usr/bin/perl
+#
+# mksnapshot.pl
+#
+# This is a very crude script to help check whether and/or what has
+# changed in generated .c files as a result of changes to xsubpp and its
+# modules.
+#
+# It finds all .xs files under the current directory, then copies to
+# another directory, each associated .c file if it exists.
+#
+# The idea is that, while cd'ed to the base of the perl distribution, you
+# run this script, which will copy all the generated .c files to one
+# directory. You then rebuild perl with the newly modified xsubpp, and
+# create a second snapshot to another directory, then compare the results.
+#
+# For example,
+#
+#    ... build perl...
+#
+#    $ mkdir /tmp/snap1 /tmp/snap2
+#    $ dist/ExtUtils-ParseXS/author/mksnapshot.pl /tmp/snap1
+#    $ git clean -xdf
+#
+#    ... modify xsubpp ...
+#    ... build perl...
+#
+#    $ dist/ExtUtils-ParseXS/author/mksnapshot.pl /tmp/snap2
+#    $ diff -ru /tmp/snap[12]
+#
+# Each snapped .c file is saved with each '/' component of its pathname
+# changed to a '='. So ext/POSIX/POSIX.c would be copied to
+#    /tmp/snap1/ext=POSIX=POSIX.c
+
+use warnings;
+use strict;
+
+use File::Find;
+use File::Copy;
+
+die "usage: $0 snapdirectory\n" unless @ARGV == 1;
+my $snapdir = shift @ARGV;
+
+die "No such directory: $snapdir\n" unless -d $snapdir;
+
+find(
+    {
+        wanted   => \&wanted,
+        no_chdir => 1,
+    },
+
+    '.'
+);
+
+
+
+sub wanted {
+    return unless /\.xs$/;
+    my $f = $_;
+    $f =~ s/\.xs$/.c/ or die;
+    return unless -f $f;
+    my $df = $f;
+    $df =~ s{^/}{};
+    $df =~ s{^\./}{};
+    $df =~ s{/}{=}g;
+    $df = "$snapdir/$df";
+    print "snapping $f\n";
+    copy($f, $df) or die "Can't copy $f to $df: $!\n";
+}