diff --git a/arch/arm/mach-ux500/mbox-db5500.c b/arch/arm/mach-ux500/mbox-db5500.c
index 2b2d51caf9d8b9f4db2e62c1eaa7a596b3313546..0127490218cdfc4bc00b107be2816a84703d6a4f 100644
--- a/arch/arm/mach-ux500/mbox-db5500.c
+++ b/arch/arm/mach-ux500/mbox-db5500.c
@@ -168,7 +168,7 @@ static ssize_t mbox_read_fifo(struct device *dev,
 	return sprintf(buf, "0x%X\n", mbox_value);
 }
 
-static DEVICE_ATTR(fifo, S_IWUGO | S_IRUGO, mbox_read_fifo, mbox_write_fifo);
+static DEVICE_ATTR(fifo, S_IWUSR | S_IRUGO, mbox_read_fifo, mbox_write_fifo);
 
 static int mbox_show(struct seq_file *s, void *data)
 {