How to prevent mouseover effect in GTK button

I have a doubt about mouseover effect when I create a button and put an image with gtk_button_set_image. If I remove the relief with gtk_button_set_relief, I can开发者_运维知识库't see the border, but when I put the mouse over the button, border appears.

Is there any solution so that this doesn't occur?

---

I guess it's just your GTK+ theme's choice.