diff --git a/fastboot/fastboot.h b/fastboot/fastboot.h
index 1d3e2b8..a84b0be 100644
--- a/fastboot/fastboot.h
+++ b/fastboot/fastboot.h
@@ -41,6 +41,7 @@
 #define FB_RESPONSE_SZ 64
 
 /* engine.c - high level command queue engine */
+int fb_getvar(struct usb_handle *usb, char *response, const char *fmt, ...);
 void fb_queue_flash(const char *ptn, void *data, unsigned sz);;
 void fb_queue_erase(const char *ptn);
 void fb_queue_format(const char *ptn, int skip_if_not_supported);