diff --git a/drivers/usb/gadget/configfs.c b/drivers/usb/gadget/configfs.c
index 0e7c1e947c0a..e0bf2b2bfc01 100644
--- a/drivers/usb/gadget/configfs.c
+++ b/drivers/usb/gadget/configfs.c
@@ -12,7 +12,7 @@
 #include "u_f.h"
 #include "u_os_desc.h"
 
-int check_user_usb_string(const char *name,
+static int check_user_usb_string(const char *name,
 		struct usb_gadget_strings *stringtab_dev)
 {
 	u16 num;
diff --git a/include/linux/usb/gadget_configfs.h b/include/linux/usb/gadget_configfs.h
index d61aebd68128..6a552dd4dec9 100644
--- a/include/linux/usb/gadget_configfs.h
+++ b/include/linux/usb/gadget_configfs.h
@@ -4,9 +4,6 @@
 
 #include <linux/configfs.h>
 
-int check_user_usb_string(const char *name,
-		struct usb_gadget_strings *stringtab_dev);
-
 #define GS_STRINGS_W(__struct, __name)	\
 static ssize_t __struct##_##__name##_store(struct config_item *item, \
 		const char *page, size_t len)		\