diff --git a/drivers/scsi/qlogicpti.c b/drivers/scsi/qlogicpti.c
index 9b827ceec50125734cd6ef3cafebb6f87949d4fe..9f10689905a8d68c3eb7be4b00561c52f7f6ac23 100644
--- a/drivers/scsi/qlogicpti.c
+++ b/drivers/scsi/qlogicpti.c
@@ -1281,7 +1281,7 @@ static struct scsi_cmnd *qlogicpti_intr_handler(struct qlogicpti *qpti)
 				      (struct scatterlist *)Cmnd->request_buffer,
 				      Cmnd->use_sg,
 				      Cmnd->sc_data_direction);
-		} else {
+		} else if (Cmnd->request_bufflen) {
 			sbus_unmap_single(qpti->sdev,
 					  (__u32)((unsigned long)Cmnd->SCp.ptr),
 					  Cmnd->request_bufflen,