diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c
index c9b01b155f65..43b97376f4e1 100644
--- a/drivers/scsi/megaraid/megaraid_sas_base.c
+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
@@ -5157,7 +5157,7 @@ static void megasas_update_ext_vd_details(struct megasas_instance *instance)
 	} else {
 		fusion->old_map_sz =  sizeof(struct MR_FW_RAID_MAP) +
 					(sizeof(struct MR_LD_SPAN_MAP) *
-					(instance->fw_supported_vd_count - 1));
+					instance->fw_supported_vd_count);
 		fusion->new_map_sz =  sizeof(struct MR_FW_RAID_MAP_EXT);
 
 		fusion->max_map_sz =
diff --git a/drivers/scsi/megaraid/megaraid_sas_fp.c b/drivers/scsi/megaraid/megaraid_sas_fp.c
index 83f69c33b01a..b2ec7a3f7650 100644
--- a/drivers/scsi/megaraid/megaraid_sas_fp.c
+++ b/drivers/scsi/megaraid/megaraid_sas_fp.c
@@ -327,7 +327,7 @@ u8 MR_ValidateMapInfo(struct megasas_instance *instance, u64 map_id)
 		expected_size = sizeof(struct MR_FW_RAID_MAP_EXT);
 	else
 		expected_size =
-			(sizeof(struct MR_FW_RAID_MAP) - sizeof(struct MR_LD_SPAN_MAP) +
+			(sizeof(struct MR_FW_RAID_MAP) +
 			(sizeof(struct MR_LD_SPAN_MAP) * le16_to_cpu(pDrvRaidMap->ldCount)));
 
 	if (le32_to_cpu(pDrvRaidMap->totalSize) != expected_size) {
diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.h b/drivers/scsi/megaraid/megaraid_sas_fusion.h
index ce84f811e5e1..5530c233fccb 100644
--- a/drivers/scsi/megaraid/megaraid_sas_fusion.h
+++ b/drivers/scsi/megaraid/megaraid_sas_fusion.h
@@ -942,7 +942,7 @@ struct MR_FW_RAID_MAP {
 	u8                  reserved2[7];
 	struct MR_ARRAY_INFO       arMapInfo[MAX_RAIDMAP_ARRAYS];
 	struct MR_DEV_HANDLE_INFO  devHndlInfo[MAX_RAIDMAP_PHYSICAL_DEVICES];
-	struct MR_LD_SPAN_MAP      ldSpanMap[1];
+	struct MR_LD_SPAN_MAP      ldSpanMap[];
 };
 
 struct IO_REQUEST_INFO {
@@ -1148,7 +1148,7 @@ typedef struct LOG_BLOCK_SPAN_INFO {
 
 struct MR_FW_RAID_MAP_ALL {
 	struct MR_FW_RAID_MAP raidMap;
-	struct MR_LD_SPAN_MAP ldSpanMap[MAX_LOGICAL_DRIVES - 1];
+	struct MR_LD_SPAN_MAP ldSpanMap[MAX_LOGICAL_DRIVES];
 } __attribute__ ((packed));
 
 struct MR_DRV_RAID_MAP {