diff --git a/lib/stm32/common/gpio_common_f24.c b/lib/stm32/common/gpio_common_f24.c
index d464a506..b8802675 100644
--- a/lib/stm32/common/gpio_common_f24.c
+++ b/lib/stm32/common/gpio_common_f24.c
@@ -178,7 +178,7 @@ void gpio_set_af(u32 gpioport, u8 alt_func_num, u16 gpios)
 		if (!((1 << i) & gpios))
 			continue;
 		afrl &= ~GPIO_AFR_MASK(i);
-		afrl |= GPIO_AFR(i, alt_func_num);
+		afrh |= GPIO_AFR(i, alt_func_num);
 	}
 
 	for (i = 8; i < 16; i++) {