diff --git a/include/scsi-lowlevel.h b/include/scsi-lowlevel.h
index f6891b7..e14cd9f 100644
--- a/include/scsi-lowlevel.h
+++ b/include/scsi-lowlevel.h
@@ -176,10 +176,6 @@ struct scsi_readtoc_list {
 	struct scsi_readtoc_desc desc[0];
 };
 
-struct scsi_compareandwrite_params {
-	uint64_t lba;
-	uint32_t num_blocks;
-};
 struct scsi_writeverify10_params {
 	uint32_t lba;
 	uint32_t num_blocks;
@@ -273,7 +269,6 @@ struct scsi_task {
 	int expxferlen;
 	unsigned char cdb[SCSI_CDB_MAX_SIZE];
 	union {
-		struct scsi_compareandwrite_params compareandwrite;
 		struct scsi_writeverify10_params   writeverify10;
 		struct scsi_writeverify12_params   writeverify12;
 		struct scsi_writeverify16_params   writeverify16;
diff --git a/lib/scsi-lowlevel.c b/lib/scsi-lowlevel.c
index 289b804..4fa13bb 100644
--- a/lib/scsi-lowlevel.c
+++ b/lib/scsi-lowlevel.c
@@ -1371,9 +1371,6 @@ scsi_cdb_compareandwrite(uint64_t lba, uint32_t xferlen, int blocksize, int wrpr
 	}
 	task->expxferlen = xferlen;
 
-	task->params.compareandwrite.lba        = lba;
-	task->params.compareandwrite.num_blocks = xferlen/blocksize;
-
 	return task;
 }