src/Pure/Thy/document_antiquotation.ML

       Name_Space.check (Context.Proof ctxt) (#2 (get_antiquotations ctxt)) (xname, pos);
   in opt s ctxt end;
 
 fun eval ctxt (opts, src) =
   let
-    val preview_ctxt = fold option opts ctxt;
+    val preview_ctxt = fold option opts (Config.put show_markup false ctxt);
     val _ = command src preview_ctxt;
 
     val print_ctxt = Context_Position.set_visible false preview_ctxt;
     val print_modes = space_explode "," (Config.get print_ctxt thy_output_modes) @ [Latex.latexN];
   in [Print_Mode.with_modes print_modes (fn () => command src print_ctxt) ()] end;