diff --git a/src/scsi/scsi_cdrom.c b/src/scsi/scsi_cdrom.c
index e099efe07..842b8cc28 100644
--- a/src/scsi/scsi_cdrom.c
+++ b/src/scsi/scsi_cdrom.c
@@ -1635,6 +1635,10 @@ scsi_cdrom_command(scsi_common_t *sc, uint8_t *cdb)
 				/* If all the flag bits are cleared, then treat it as a non-data command. */
 				if ((cdb[9] == 0x00) && ((cdb[10] & 0x07) == 0x00))
 					dev->sector_len = 0;
+				else if ((cdb[9] == 0x00) && ((cdb[10] & 0x07) != 0x00)) {
+					scsi_cdrom_invalid_field(dev);
+					break;
+				}
 				break;
 			case GPCMD_READ_CD_OLD:
 			case GPCMD_READ_CD:
@@ -1653,6 +1657,10 @@ scsi_cdrom_command(scsi_common_t *sc, uint8_t *cdb)
 				/* If all the flag bits are cleared, then treat it as a non-data command. */
 				if ((cdb[9] == 0x00) && ((cdb[10] & 0x07) == 0x00))
 					dev->sector_len = 0;
+				else if ((cdb[9] == 0x00) && ((cdb[10] & 0x07) != 0x00)) {
+					scsi_cdrom_invalid_field(dev);
+					break;
+				}
 				break;
 		}