diff --git a/drivers/usb/renesas_usbhs/common.c b/drivers/usb/renesas_usbhs/common.c
index ce54abf..1ce32d9 100644
--- a/drivers/usb/renesas_usbhs/common.c
+++ b/drivers/usb/renesas_usbhs/common.c
@@ -95,7 +95,7 @@
 /*
  *		syscfg functions
  */
-void usbhs_sys_clock_ctrl(struct usbhs_priv *priv, int enable)
+static void usbhs_sys_clock_ctrl(struct usbhs_priv *priv, int enable)
 {
 	usbhs_bset(priv, SYSCFG, SCKE, enable ? SCKE : 0);
 }
diff --git a/drivers/usb/renesas_usbhs/common.h b/drivers/usb/renesas_usbhs/common.h
index 46c9fd2..3199d37 100644
--- a/drivers/usb/renesas_usbhs/common.h
+++ b/drivers/usb/renesas_usbhs/common.h
@@ -283,7 +283,6 @@
 /*
  * sysconfig
  */
-void usbhs_sys_clock_ctrl(struct usbhs_priv *priv, int enable);
 void usbhs_sys_host_ctrl(struct usbhs_priv *priv, int enable);
 void usbhs_sys_function_ctrl(struct usbhs_priv *priv, int enable);