diff --git a/cpdfcommand.ml b/cpdfcommand.ml
index d7f602f..c236f5c 100644
--- a/cpdfcommand.ml
+++ b/cpdfcommand.ml
@@ -3655,7 +3655,8 @@ let go () =
                         in
                         let outpdf =
                           Pdfmerge.merge_pdfs
-                            args.retain_numbering args.remove_duplicate_fonts ~process_struct_trees:args.process_struct_trees names pdfs rangenums
+                            args.retain_numbering args.remove_duplicate_fonts ~process_struct_trees:args.process_struct_trees
+                            ~add_toplevel_document:(args.subformat = Some Cpdfua.PDFUA2) names pdfs rangenums
                         in
                           if args.remove_duplicate_streams then Pdfmerge.remove_duplicate_fonts outpdf; (* JBIG2 Globals *)
                           write_pdf false outpdf
diff --git a/cpdfmanual.pdf b/cpdfmanual.pdf
index eecd2f2..cfceca2 100644
Binary files a/cpdfmanual.pdf and b/cpdfmanual.pdf differ
diff --git a/cpdfmanual.tex b/cpdfmanual.tex
index c08665f..043a38f 100644
--- a/cpdfmanual.tex
+++ b/cpdfmanual.tex
@@ -5218,7 +5218,7 @@ A PDF may contain, in addition to its graphical content, a tree of information c
 
 When drawing, Cpdf can add such structure information. Partly this can happen automatically, partly it is for the user to add the tags.
 
-NB: These facilities are presently limited to drawing new PDFs. To draw on an existing PDF draw a new one, and then stamp it on top and the structure information will be merged.
+NB: These facilities are presently limited to drawing new PDFs.
 
 To enable the generation of structure information, we add \texttt{-draw-struct-tree} to our command: