diff --git a/src/render/vbo/Render_alternate.cpp b/src/render/vbo/Render_alternate.cpp
index d7eee7f76959f405328bc06632ca36bf7ed7623e..fa6974c82630c7406e3dd0d6870342d55d99e93c 100644
--- a/src/render/vbo/Render_alternate.cpp
+++ b/src/render/vbo/Render_alternate.cpp
@@ -1264,8 +1264,8 @@ void Render_alternate::update_vertical_line(){
     if (_mouse_pressed_inside_container)
         set_vertical_line(0);
     else {
-        set_vertical_line(render_to_trace_x( screen_to_render_x(_mouse_x)));
         Element_pos d = render_to_trace_x( screen_to_render_x(_mouse_x));
+        set_vertical_line( d );
         _core->launch_action(_core->_STATE_UPDATE_VARVALUES, &d);//update the value of the variables to display
     }
     updateGL();