diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 78fce1b..33d2cf2 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -32,7 +32,7 @@
 static LIST_HEAD(dwc3_list);
 /* -------------------------------------------------------------------------- */
 
-void dwc3_set_mode(struct dwc3 *dwc, u32 mode)
+static void dwc3_set_mode(struct dwc3 *dwc, u32 mode)
 {
 	u32 reg;
 
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 5288a18..72d2fcd 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -987,7 +987,6 @@ struct dwc3_gadget_ep_cmd_params {
 #define DWC3_HAS_OTG			BIT(3)
 
 /* prototypes */
-void dwc3_set_mode(struct dwc3 *dwc, u32 mode);
 int dwc3_gadget_resize_tx_fifos(struct dwc3 *dwc);
 
 #ifdef CONFIG_USB_DWC3_HOST