[GUI] how to correctly scale GuiButton

I have a GuiButton that is being instantiated with an offset value. It is then being transformed as below before being drawn:

GlStateManager.translate(guiLeft, guiTop, 0);
GlStateManager.scale(guiScale, guiScale, guiScale);

How can I transform the values of `mouseX` and `mouseY` to essentially reverse the scaling, so that when passed to `drawButton` they are of same scale and position of the original coordinates, meaning that the hover check and the like will work?

Thanks in advance.