diff --git a/Makefile b/Makefile
index 4644d56..17577c9 100644
--- a/Makefile
+++ b/Makefile
@@ -8,7 +8,7 @@ DOC = cpdfunicodedata cpdferror cpdfdebug cpdfjson cpdfstrftime cpdfcoord \
       cpdfsqueeze cpdfdraft cpdfspot cpdfpagelabels cpdfcreate cpdfannot \
       cpdfxobject cpdfimpose cpdfchop cpdftweak cpdftexttopdf cpdftoc \
       cpdfjpeg cpdfjpeg2000 cpdfpng cpdfimage cpdfdraw cpdfcomposition \
-      cpdfshape cpdfcolours cpdfdrawcontrol cpdfprinttree cpdfst cpdfua \
+      cpdfshape cpdfcolours cpdfdrawcontrol cpdfprinttree cpdfua \
       cpdfcommand
 
 MODS = $(NONDOC) $(DOC)
diff --git a/cpdfcommand.ml b/cpdfcommand.ml
index bf8f20d..df8c252 100644
--- a/cpdfcommand.ml
+++ b/cpdfcommand.ml
@@ -3492,6 +3492,7 @@ let go () =
                 | [pdf] ->
                     if hd ranges <> "all" then
                       let range = parse_pagespec pdf (hd ranges) in
+                        (* FIXME STRUCTURE TREE TRIM *)
                         let newpdf = Pdfpage.pdf_of_pages ~retain_numbering:args.retain_numbering pdf range in
                           write_pdf false newpdf
                     else
@@ -3920,6 +3921,7 @@ let go () =
         | _ -> error "Split: bad parameters"
       end
   | Some (SplitOnBookmarks level) ->
+      (* FIXME STRUCTURE TREE TRIM *)
       begin match args.out with
         | File output_spec ->
             let pdf = get_single_pdf args.op false in
@@ -3931,6 +3933,7 @@ let go () =
         | NoOutputSpecified -> error "Split: No output format specified"
       end
   | Some (SplitMax s) ->
+      (* FIXME STRUCTURE TREE TRIM *)
       begin match args.out with
         | File output_spec ->
             let pdf = get_single_pdf args.op false in
@@ -3941,6 +3944,7 @@ let go () =
         | NoOutputSpecified -> error "Split: No output format specified"
       end
   | Some Spray ->
+      (* FIXME STRUCTURE TREE TRIM *)
       begin match args.inputs, args.out with
         | (_, pagespec, _, _, _, _)::_, File output_spec ->
             let pdf = get_single_pdf args.op false in
diff --git a/cpdfst.ml b/cpdfst.ml
deleted file mode 100644
index 6e12d90..0000000
--- a/cpdfst.ml
+++ /dev/null
@@ -1,5 +0,0 @@
-(* Operations on structure trees. *)
-open Pdfutil
-
-let trim_structure_tree pdf range =
-  flprint "trim_structure_tree\n"
diff --git a/cpdfst.mli b/cpdfst.mli
deleted file mode 100644
index a0ac2d0..0000000
--- a/cpdfst.mli
+++ /dev/null
@@ -1,4 +0,0 @@
-(** Structure trees *)
-
-(** Trim structure tree to remove parts marked as not in the page range given. *)
-val trim_structure_tree : Pdf.t -> int list -> unit