diff --git a/drivers/usb/core/phy.h b/drivers/usb/core/phy.h
index 605555901d443457b4414359716d3584f1a91f68..bbc96938307498cead99de42f03f619a7bbe5e2a 100644
--- a/drivers/usb/core/phy.h
+++ b/drivers/usb/core/phy.h
@@ -1,3 +1,4 @@
+struct device;
 struct usb_phy_roothub;
 
 struct usb_phy_roothub *usb_phy_roothub_alloc(struct device *dev);