diff --git a/drivers/scsi/pmcraid.c b/drivers/scsi/pmcraid.c
index bd6f743..f413ef7 100644
--- a/drivers/scsi/pmcraid.c
+++ b/drivers/scsi/pmcraid.c
@@ -4315,6 +4315,7 @@
 	.this_id = -1,
 	.sg_tablesize = PMCRAID_MAX_IOADLS,
 	.max_sectors = PMCRAID_IOA_MAX_SECTORS,
+	.no_write_same = 1,
 	.cmd_per_lun = PMCRAID_MAX_CMD_PER_LUN,
 	.use_clustering = ENABLE_CLUSTERING,
 	.shost_attrs = pmcraid_host_attrs,