diff --git a/drivers/char/mmtimer.c b/drivers/char/mmtimer.c
index 70b774f..1f0f2b6 100644
--- a/drivers/char/mmtimer.c
+++ b/drivers/char/mmtimer.c
@@ -63,7 +63,7 @@
  */
 static unsigned long mmtimer_femtoperiod = 0;
 
-static struct file_operations mmtimer_fops = {
+static const struct file_operations mmtimer_fops = {
 	.owner =	THIS_MODULE,
 	.mmap =		mmtimer_mmap,
 	.ioctl =	mmtimer_ioctl,