diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index e19c677..bd0e3c6 100644
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -247,6 +247,7 @@
 #endif
 
 extern struct backing_dev_info default_backing_dev_info;
+extern struct backing_dev_info noop_backing_dev_info;
 void default_unplug_io_fn(struct backing_dev_info *bdi, struct page *page);
 
 int writeback_in_progress(struct backing_dev_info *bdi);