diff --git a/drivers/scsi/pdc_adma.c b/drivers/scsi/pdc_adma.c
index 53b8db4..9820f27 100644
--- a/drivers/scsi/pdc_adma.c
+++ b/drivers/scsi/pdc_adma.c
@@ -158,7 +158,7 @@
 	.bios_param		= ata_std_bios_param,
 };
 
-static struct ata_port_operations adma_ata_ops = {
+static const struct ata_port_operations adma_ata_ops = {
 	.port_disable		= ata_port_disable,
 	.tf_load		= ata_tf_load,
 	.tf_read		= ata_tf_read,