diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index fcbc26a..2742e1a 100644
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -14,6 +14,7 @@
 #include <linux/kernel.h>
 #include <linux/fs.h>
 #include <linux/sched.h>
+#include <linux/timer.h>
 #include <linux/writeback.h>
 #include <asm/atomic.h>
 
@@ -88,6 +89,8 @@
 
 	struct device *dev;
 
+	struct timer_list laptop_mode_wb_timer;
+
 #ifdef CONFIG_DEBUG_FS
 	struct dentry *debug_dir;
 	struct dentry *debug_stats;