diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 989b775..3fd0820 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -2331,7 +2331,7 @@
 	DPRINTK("ATAPI request sense\n");
 
 	/* FIXME: is this needed? */
-	memset(cmd->sense_buffer, 0, sizeof(cmd->sense_buffer));
+	memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
 
 	ap->ops->tf_read(ap, &qc->tf);