diff --git a/cpu/pxa/usb.c b/cpu/pxa/usb.c
index 3c11d4d..d2812a4 100644
--- a/cpu/pxa/usb.c
+++ b/cpu/pxa/usb.c
@@ -28,7 +28,7 @@
 
 #include <asm/arch/pxa-regs.h>
 
-int usb_cpu_init()
+int usb_cpu_init(void)
 {
 #if defined(CONFIG_CPU_MONAHANS)
 	/* Enable USB host clock. */
@@ -65,7 +65,7 @@
 	return 0;
 }
 
-int usb_cpu_stop()
+int usb_cpu_stop(void)
 {
 	UHCHR |= UHCHR_FHR;
 	udelay(11);
@@ -86,7 +86,7 @@
 	return 0;
 }
 
-int usb_cpu_init_fail()
+int usb_cpu_init_fail(void)
 {
 	return 0;
 }