diff --git a/include/linux/sm501.h b/include/linux/sm501.h
index 6ea3900..a8d02f3 100644
--- a/include/linux/sm501.h
+++ b/include/linux/sm501.h
@@ -156,7 +156,7 @@
 	struct sm501_platdata_fb	*fb;
 
 	int				 flags;
-	unsigned			 gpio_base;
+	int				 gpio_base;
 
 	int	(*get_power)(struct device *dev);
 	int	(*set_power)(struct device *dev, unsigned int on);