diff --git a/Changes b/Changes
index ac8efea..83f5eec 100644
--- a/Changes
+++ b/Changes
@@ -13,6 +13,7 @@ o New -decompress-just-content for easier content stream debugging
 Fixes:
 
 * Sanitizes inputs to prevent command injection attacks
+o Fix PMAXX et al. w.r.t -add-rectangle
 
 * = Supported by a grant from NLnet
 
diff --git a/cpdfaddtext.ml b/cpdfaddtext.ml
index 2137683..6b61c90 100644
--- a/cpdfaddtext.ml
+++ b/cpdfaddtext.ml
@@ -579,7 +579,7 @@ let
                 !pdf
 
 let addrectangle
-  fast (w, h) colour outline linewidth opacity position relative_to_cropbox
+  fast coord colour outline linewidth opacity position relative_to_cropbox
   underneath range pdf
 =
   let addrectangle_page _ page =
@@ -607,6 +607,11 @@ let addrectangle
       else
         Pdf.parse_rectangle pdf page.Pdfpage.mediabox
     in
+    let w, h =
+      match Cpdfcoord.parse_units_string pdf page coord with
+      | [w; h] -> w, h
+      | _ -> error "bad coordinate specification"
+    in
     let x, y, _ =
       Cpdfposition.calculate_position false w mediabox position
     in
diff --git a/cpdfaddtext.mli b/cpdfaddtext.mli
index 8992d50..421ac54 100644
--- a/cpdfaddtext.mli
+++ b/cpdfaddtext.mli
@@ -48,10 +48,10 @@ val addtexts :
     Pdf.t ->(*pdf*)
     Pdf.t
 
-(** Add a rectangle to the given pages. [addrectangle fast (w, h) colour outline linewidth opacity position relative_to_cropbox underneath range pdf]. *) 
+(** Add a rectangle to the given pages. [addrectangle fast coordinate colour outline linewidth opacity position relative_to_cropbox underneath range pdf]. *) 
 val addrectangle :
     bool ->
-    float * float ->
+    string ->
     colour ->
     bool ->
     float ->
diff --git a/cpdfcommand.ml b/cpdfcommand.ml
index 3b26c71..6403686 100644
--- a/cpdfcommand.ml
+++ b/cpdfcommand.ml
@@ -4590,7 +4590,7 @@ let go () =
         let range = parse_pagespec_allow_empty pdf (get_pagespec ()) in
           write_pdf false
             (Cpdfaddtext.addrectangle
-               args.fast (Cpdfcoord.parse_coordinate pdf args.coord)
+               args.fast args.coord
                args.color args.outline args.linewidth args.opacity args.position
                args.relative_to_cropbox args.underneath range pdf)
   | Some (AddBookmarks file) ->
diff --git a/cpdfcoord.mli b/cpdfcoord.mli
index 5e75334..95234d2 100644
--- a/cpdfcoord.mli
+++ b/cpdfcoord.mli
@@ -14,5 +14,7 @@ val parse_coordinate : Pdf.t -> string -> float * float
 (** Read a list of coordinates from a string *)
 val parse_coordinates : Pdf.t -> string -> (float * float) list
 
+val parse_units_string : Pdf.t -> Pdfpage.t -> string -> float list
+
 (** Read a single number from a string *)
 val parse_single_number : Pdf.t -> string -> float
diff --git a/cpdfimpose.ml b/cpdfimpose.ml
index fcc7a15..82e594b 100644
--- a/cpdfimpose.ml
+++ b/cpdfimpose.ml
@@ -188,7 +188,7 @@ let add_border linewidth ~fast pdf =
   let firstpage = hd (Pdfpage.pages_of_pagetree pdf) in
   let _, _, w, h = Pdf.parse_rectangle pdf firstpage.Pdfpage.mediabox in
     Cpdfaddtext.addrectangle
-      fast (w -. linewidth, h -. linewidth) (RGB (0., 0., 0.)) true linewidth 1. (Cpdfposition.BottomLeft (linewidth /. 2., linewidth /. 2.))
+      fast (string_of_float (w -. linewidth) ^ " " ^ string_of_float (h -. linewidth)) (RGB (0., 0., 0.)) true linewidth 1. (Cpdfposition.BottomLeft (linewidth /. 2., linewidth /. 2.))
       false false (ilist 1 (Pdfpage.endpage pdf)) pdf
 
 let impose ~process_struct_tree ~x ~y ~fit ~columns ~rtl ~btt ~center ~margin ~spacing ~linewidth ~fast pdf =