diff --git a/test-tool/test_writesame10_unmap_until_end.c b/test-tool/test_writesame10_unmap_until_end.c
index 2476905..0210961 100644
--- a/test-tool/test_writesame10_unmap_until_end.c
+++ b/test-tool/test_writesame10_unmap_until_end.c
@@ -53,11 +53,9 @@ test_writesame10_unmap_until_end(void)
                         i * block_size, block_size, 0, 0, 0, 0, 0, scratch,
                         EXPECT_STATUS_GOOD);
 
-                // write 0-buffer to entire range.
-                memset(scratch, 0, block_size * i);
                 logging(LOG_VERBOSE, "Unmap %d blocks using WRITESAME10", i);
                 WRITESAME10(sd, num_blocks - i,
-                            block_size, i, 0, 1, 0, 0, scratch,
+                            block_size, 0, 0, 1, 0, 0, scratch,
                             EXPECT_STATUS_GOOD);
 
                 if (rc16->lbprz) {
diff --git a/test-tool/test_writesame16_unmap_until_end.c b/test-tool/test_writesame16_unmap_until_end.c
index 2bf2ec6..6b18c1f 100644
--- a/test-tool/test_writesame16_unmap_until_end.c
+++ b/test-tool/test_writesame16_unmap_until_end.c
@@ -58,7 +58,7 @@ test_writesame16_unmap_until_end(void)
                 logging(LOG_VERBOSE, "Unmap %d blocks using WRITESAME16", i);
                 memset(scratch, 0, block_size);
                 WRITESAME16(sd, num_blocks - i,
-                            block_size, i, 0, 1, 0, 0, scratch,
+                            block_size, 0, 0, 1, 0, 0, scratch,
                             EXPECT_STATUS_GOOD);
 
                 if (rc16->lbprz) {