How to display integers instead of floats in a pie chart legend?

Question

My code:

    ggplot(faixa_vol_op_contagem, aes(x = "", y = num_vol_op, fill = FAIXA_DESENROLA)) +
       geom_bar(stat = "identity") +
       coord_polar("y", start = 0) +
       theme_void()

returns this:

Instead of 1, 1.25 and so on, I just want 1 and 2. How can I do this?