diff --git a/guile/scripts/Makefile.am b/guile/scripts/Makefile.am
index bacb0501..c8465965 100644
--- a/guile/scripts/Makefile.am
+++ b/guile/scripts/Makefile.am
@@ -22,7 +22,8 @@ EXTRA_DIST=			\
 	msgs-per-hour.scm	\
 	msgs-per-month.scm	\
 	msgs-per-day.scm	\
-	msgs-per-year-month.scm
+	msgs-per-year-month.scm \
+	find-dups.scm
 
 muguiledistscriptdir      = $(pkgdatadir)/scripts/
 muguiledistscript_SCRIPTS = $(EXTRA_DIST)
diff --git a/guile/scripts/find-dups.scm b/guile/scripts/find-dups.scm
new file mode 100755
index 00000000..6262956a
--- /dev/null
+++ b/guile/scripts/find-dups.scm
@@ -0,0 +1,96 @@
+#!/bin/sh
+exec guile -e main -s $0 $@
+!#
+;;
+;; Copyright (C) 2013 Dirk-Jan C. Binnema <djcb@djcbsoftware.nl>
+;;
+;; This program is free software; you can redistribute it and/or modify it
+;; under the terms of the GNU General Public License as published by the
+;; Free Software Foundation; either version 3, or (at your option) any
+;; later version.
+;;
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+;;
+
+;; You should have received a copy of the GNU General Public License
+;; along with this program; if not, write to the Free Software Foundation,
+;; Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+
+;; INFO: find duplicate messages
+;; INFO:   --muhome=<muhome>: path to mu home dir
+
+(use-modules (mu) (mu script) (mu stats))
+(use-modules (ice-9 getopt-long) (ice-9 optargs)
+  (ice-9 popen) (ice-9 format) (ice-9 rdelim))
+
+(define (md5sum path)
+  (let* ((port (open-pipe* OPEN_READ "md5sum" path))
+	  (md5 (read-delimited " " port)))
+    (close-pipe port)
+    md5))
+
+
+(define (find-dups)
+  (let ((id-table (make-hash-table 20000)))
+    ;; fill the hash with <msgid-size> => <list of paths>
+    (mu:for-each-message
+      (lambda (msg)
+	(let* ((id (format #f "~a-~d" (mu:message-id msg)
+		    (mu:size msg)))
+	       (lst (hash-ref id-table id)))
+	  (if lst
+	    (set! lst (cons (mu:path msg) lst))
+	    (set! lst (list (mu:path msg))))
+	  (hash-set! id-table id lst))))
+    ;; list all the paths with multiple elements; check the md5sum to
+    ;; make 100%-minus-ε sure they are really the same file.
+    (hash-for-each
+      (lambda (id paths)
+	(if (> (length paths) 1)
+	  (let ((hash (make-hash-table 10)))
+	    (for-each
+	      (lambda (path)
+	      	(let* ((md5 (md5sum path)) (lst (hash-ref hash md5)))
+		  (if lst
+	      	    (set! lst (cons path lst))
+	      	    (set! lst (list path)))
+	      	  (hash-set! hash md5 lst)))
+ 	      paths)
+	    ;; hash now maps the md5sum to the messages...
+	    (hash-for-each
+	      (lambda (md5 mpaths)
+	    	(if (> (length mpaths) 1)
+		  (begin
+		    (format #t "md5sum: ~a:\n" md5)
+		    (let ((num 1))
+		      (for-each
+			(lambda (path)
+			  (format #t "\t~d. ~a\n" num path)
+			  (set! num (+ 1 num)))
+			mpaths)))))
+	      hash))))
+      id-table)))
+
+
+
+(define (main args)
+  "Run some statistics function.
+Interpret argument-list ARGS (like command-line
+arguments). Possible arguments are:
+  --muhome (path to alternative mu home directory)."
+  (setlocale LC_ALL "")
+  (let* ((optionspec   '( (muhome     (value #t))
+			  (help       (single-char #\h) (value #f))))
+	  (options (getopt-long args optionspec))
+	  (help (option-ref options 'help #f))
+	  (muhome (option-ref options 'muhome #f)))
+    (mu:initialize muhome)
+    (find-dups)))
+
+
+;; Local Variables:
+;; mode: scheme
+;; End: