diff --git a/gtk2_ardour/editor_ops.cc b/gtk2_ardour/editor_ops.cc
index e2a378759d..a0370d0d7e 100644
--- a/gtk2_ardour/editor_ops.cc
+++ b/gtk2_ardour/editor_ops.cc
@@ -1789,49 +1789,12 @@ Editor::temporal_zoom_step_scale (bool zoom_out, double scale)
 		}
 	}
 
-	// ToDo:   encapsulate all of this into something like editor::get_session_extents() or editor::leftmost(), rightmost()
-	{
-		//ToDo: also incorporate automation regions (in case the session has no audio/midi but is just used for automating plugins or the like)
-
-		//calculate the extents of all regions in every playlist
-		framecnt_t session_extent_start = 0;
-		framecnt_t session_extent_end = 0;
-		{
-			boost::shared_ptr<RouteList> rl = _session->get_routes();
-			for (RouteList::iterator r = rl->begin(); r != rl->end(); ++r) {
-				boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*r);
-				if (tr) {
-					boost::shared_ptr<Playlist> pl = tr->playlist();
-					if (pl) {
-						pair<framepos_t, framepos_t> e;
-						e = pl->get_extent();
-						if (e.first < session_extent_start) {
-							session_extent_start = e.first;
-						}
-						if (e.second > session_extent_end) {
-							session_extent_end = e.second;
-						}
-					}
-				}
-			}
-		}
-		framecnt_t session_extents = session_extent_end - session_extent_start;
-
-		//in a session with no regions, use the start/end markers to set max zoom
-		framecnt_t const session_length = _session->current_end_frame() - _session->current_start_frame ();
-		if ( session_length > session_extents )
-			session_extents = session_length;
-
-		//in a session with no regions or start/end markers, use 2 minutes to set max zoom
-		framecnt_t const min_length = _session->nominal_frame_rate()*60*2;
-		if ( min_length > session_extents )
-			session_extents = min_length;
-
-		//convert to samples-per-pixel and limit our zoom to this value
-		framecnt_t session_extents_pp = session_extents / _visible_canvas_width;
-		if (nspp > session_extents_pp)
-			nspp = session_extents_pp;
-	}
+	//zoom-behavior-tweaks
+	//limit our maximum zoom to the session gui extents value (+10%)
+	std::pair<framepos_t, framepos_t> ext = session_gui_extents();
+	framecnt_t session_extents_pp = ( ext.second - ext.first )  / _visible_canvas_width;
+	if (nspp > session_extents_pp * 1.1)
+		nspp = session_extents_pp * 1.1;
 
 	temporal_zoom (nspp);
 }