diff --git a/drivers/gpio/mpc83xx_gpio.c b/drivers/gpio/mpc83xx_gpio.c
index a9afcb2dd6f1a7356b302f6ab74b87bb8aa52e78..e167852b83c27f11fea8aaae7f9491c927188b9e 100644
--- a/drivers/gpio/mpc83xx_gpio.c
+++ b/drivers/gpio/mpc83xx_gpio.c
@@ -163,7 +163,7 @@ int gpio_set_value(unsigned gpio, int value)
 }
 
 /* Configure GPIO registers early */
-void mpc83xx_gpio_init_f()
+void mpc83xx_gpio_init_f(void)
 {
 	immap_t *im = (immap_t *)CONFIG_SYS_IMMR;
 
@@ -187,7 +187,7 @@ void mpc83xx_gpio_init_f()
 }
 
 /* Initialize GPIO soft-copies */
-void mpc83xx_gpio_init_r()
+void mpc83xx_gpio_init_r(void)
 {
 #if MPC83XX_GPIO_CTRLRS >= 1
 	gpio_output_value[0] = CONFIG_MPC83XX_GPIO_0_INIT_VALUE;