diff --git a/Changes b/Changes
index cdf7457..a07960f 100644
--- a/Changes
+++ b/Changes
@@ -1,5 +1,6 @@
 2.5 (Upcoming 2022)
 
+o Append e.g DUP2 to a page range to make 1,2,3 --> 1,1,2,2,3,3 etc.
 o The -list-fonts operation now obeys the range
 o New operation -print-font-table gives (charcode, unicode, glyph name) triples
 o Can now search for a font by real name with -font
diff --git a/cpdfpagespec.ml b/cpdfpagespec.ml
index e383421..194d59c 100644
--- a/cpdfpagespec.ml
+++ b/cpdfpagespec.ml
@@ -92,7 +92,11 @@ let fixup_negatives endpage = function
 let invert_range endpage r =
   option_map (fun p -> if mem p r then None else Some p) (ilist 1 endpage)
 
+let duplicate_range n r =
+  flatten (map (fun x -> many x n) r)
+
 let rec parse_pagespec_inner endpage pdf spec =
+  let spec = if spec = "" then "all" else spec in
   let spec = space_string spec in
     if endpage < 1 then raise (Pdf.PDFError "This PDF file has no pages and is therefore malformed") else
       let numbers =
@@ -100,6 +104,14 @@ let rec parse_pagespec_inner endpage pdf spec =
           match explode spec with
           | 'N'::'O'::'T'::r ->
               invert_range endpage (parse_pagespec_inner endpage pdf (implode r))
+          | x::'D'::'U'::'P'::r ->
+              duplicate_range (int_of_string (implode [x])) (parse_pagespec_inner endpage pdf (implode r))
+          | x::y::'D'::'U'::'P'::r ->
+              duplicate_range (int_of_string (implode [x; y])) (parse_pagespec_inner endpage pdf (implode r))
+          | x::y::z::'D'::'U'::'P'::r ->
+              duplicate_range (int_of_string (implode [x; y; z])) (parse_pagespec_inner endpage pdf (implode r))
+          | x::y::z::a::'D'::'U'::'P'::r ->
+              duplicate_range (int_of_string (implode [x; y; z; a])) (parse_pagespec_inner endpage pdf (implode r))
           | _ ->
             match rev (explode spec) with
             | ['n'; 'e'; 'v'; 'e'] ->
diff --git a/cpdfpagespec.mli b/cpdfpagespec.mli
index aa575e6..018a4d0 100644
--- a/cpdfpagespec.mli
+++ b/cpdfpagespec.mli
@@ -12,7 +12,8 @@
 {- The word all is the same as 1-end.}
 {- A range must contain no spaces.}
 {- A tilde (~) defines a page number counting from the end of the document rather than the beginning. Page ~1 is the last page, ~2 the penultimate page etc.}
-{- Prepending NOT to a whole page range inverts it.}
+{- Prepending NOT to a whole page range inverts it, once the whole is parsed. }
+{- Appending DUP2 to a whole page range duplicates each page twice (or 3, or 4 etc. times), once the whole is parsed. }
 }
 *)