diff --git a/scst/src/scst_lib.c b/scst/src/scst_lib.c
index 02ec6c5e7..fadec75e3 100644
--- a/scst/src/scst_lib.c
+++ b/scst/src/scst_lib.c
@@ -554,17 +554,17 @@ static const struct scst_sdbops scst_scsi_op_table[] = {
 	{.ops = 0x04, .devkey = "M    O O        ",
 	 .info_op_name = "FORMAT UNIT",
 	 .info_data_direction = SCST_DATA_NONE,
-	 .info_op_flags = SCST_LONG_TIMEOUT|SCST_WRITE_MEDIUM,
+	 .info_op_flags = SCST_LONG_TIMEOUT|SCST_WRITE_MEDIUM|SCST_STRICTLY_SERIALIZED,
 	 .get_cdb_info = get_cdb_info_fmt},
 	{.ops = 0x04, .devkey = " O              ",
 	 .info_op_name = "FORMAT MEDIUM",
-	 .info_data_direction = SCST_DATA_WRITE,
+	 .info_data_direction = SCST_DATA_WRITE|SCST_STRICTLY_SERIALIZED,
 	 .info_op_flags = SCST_LONG_TIMEOUT|SCST_WRITE_MEDIUM,
 	 .info_len_off = 3, .get_cdb_info = get_cdb_info_len_2},
 	{.ops = 0x04, .devkey = "  O             ",
 	 .info_op_name = "FORMAT",
 	 .info_data_direction = SCST_DATA_NONE,
-	 .info_op_flags = SCST_WRITE_MEDIUM,
+	 .info_op_flags = SCST_WRITE_MEDIUM|SCST_STRICTLY_SERIALIZED,
 	 .get_cdb_info = get_cdb_info_none},
 	{.ops = 0x05, .devkey = "VMVVVV  V       ",
 	 .info_op_name = "READ BLOCK LIMITS",