diff --git a/examples/rectangle.ml b/examples/rectangle.ml
index ab9814b..1970f70 100644
--- a/examples/rectangle.ml
+++ b/examples/rectangle.ml
@@ -17,8 +17,9 @@ let view dims padding =
     |. int attr "x"      padding
     |. int attr "y"      padding
   in
-  svg <.> rect
+  select "body"
+  |. svg <.> rect
 ;;
 
 let _ =
-  run "body" () (view { width = 300; height = 300 } 20)
+  run () (view { width = 300; height = 300 } 20)
diff --git a/examples/todo.ml b/examples/todo.ml
index 504ec61..a653805 100644
--- a/examples/todo.ml
+++ b/examples/todo.ml
@@ -260,7 +260,8 @@ module View = struct
     |. html (fun _ _ _ -> content)
 
   let make k =
-    seq [todoapp k; low_footer]
+    nest (select "body")
+      [todoapp k; low_footer]
 end
 
 module Storage : sig
@@ -297,7 +298,7 @@ let main_lazy () =
    * the code above without lwt, which will improve performance by a bit. *)
   let model = ref { Model.init with Model.items = Storage.get () } in
   let rec go () =
-    D3.run "body" !model (Lazy.force view)
+    D3.run !model (Lazy.force view)
   and view = lazy (View.make (fun e ->
     model := Event.handle e !model;
     Storage.set (!model).Model.items;
@@ -313,15 +314,14 @@ let main_lwt () =
   in
   let view = View.make push in
   let init = { Model.init with Model.items = Storage.get () } in
-  D3.run "body" init view;
+  D3.run init view;
   Lwt_stream.fold (fun e m ->
     let m' = Event.handle e m in
     Storage.set m'.Model.items;
-    D3.run "body" m' view;
+    D3.run m' view;
     m')
   stream init
 ;;
 
-
 let _ =
   Lwt_js_events.async main_lwt
diff --git a/lib/d3.ml b/lib/d3.ml
index b06500e..3aa7985 100644
--- a/lib/d3.ml
+++ b/lib/d3.ml
@@ -181,11 +181,11 @@ module E = struct
   let handle name f = _handler name f
 end
 
-let run selector data t =
+let run ?(node=Js.Unsafe.global##document) data t =
   let cxt =
     let open Js.Unsafe in
     meth_call
-      (d3_select (Js.string selector))
+      (d3_select node)
       "datum" [| inject data |]
   in
   ignore (t cxt)
diff --git a/lib/d3.mli b/lib/d3.mli
index c54822a..038747c 100644
--- a/lib/d3.mli
+++ b/lib/d3.mli
@@ -298,11 +298,14 @@ module E : sig
   val handle : string -> (Dom_html.event, 'a) handler -> ('a, 'a) t
 end
 
-val run : string -> 'a -> ('a, _) t -> unit
-(** [run selector datum op] selects the first element that matches [selector],
-    binds [datum] to it, and runs [op] on that element. This is the only way to
-    run a D3.t operation. It can be used in a variety of contexts, however its
-    indended use is in an event loop of an application, along these lines:
+val run : ?node:Dom.node Js.t -> 'a -> ('a, _) t -> unit
+(** [run ?node datum op] binds [datum] to [node] and runs [op] on that element.
+    If [node] is not provided, then the current document node will be used
+    instead.
+
+    This is the only way to run a D3.t operation. It can be used in a variety
+    of contexts, however its indended use is in an event loop of an
+    application, along these lines:
 
 {[
 let main () =
@@ -313,4 +316,4 @@ let main () =
     D3.run "body" !model view)
 ;;
 
-main ()]}*)
+main ()]} *)