diff --git a/sound/usb/quirks.h b/sound/usb/quirks.h
index 03e5e94..0ca9e91 100644
--- a/sound/usb/quirks.h
+++ b/sound/usb/quirks.h
@@ -1,6 +1,10 @@
 #ifndef __USBAUDIO_QUIRKS_H
 #define __USBAUDIO_QUIRKS_H
 
+struct audioformat;
+struct snd_usb_endpoint;
+struct snd_usb_substream;
+
 int snd_usb_create_quirk(struct snd_usb_audio *chip,
 			 struct usb_interface *iface,
 			 struct usb_driver *driver,
@@ -20,4 +24,10 @@
 int snd_usb_is_big_endian_format(struct snd_usb_audio *chip,
 				 struct audioformat *fp);
 
+void snd_usb_endpoint_start_quirk(struct snd_usb_endpoint *ep);
+
+void snd_usb_ctl_msg_quirk(struct usb_device *dev, unsigned int pipe,
+			   __u8 request, __u8 requesttype, __u16 value,
+			   __u16 index, void *data, __u16 size);
+
 #endif /* __USBAUDIO_QUIRKS_H */