diff --git a/modules/disk.sh b/modules/disk.sh
index e2359da..7c82470 100644
--- a/modules/disk.sh
+++ b/modules/disk.sh
@@ -96,7 +96,7 @@ disk_align_sectors() {
 # $2 - destination file
 # $3 - offset in number of 512 sectors
 disk_write_at_offset() {
-  run_and_log_cmd "dd if=${1} of=${2} seek=${3} conv=sparse status=none"
+  run_and_log_cmd "dd if=${1} of=${2} seek=${3} conv=sparse,notrunc status=none"
 }
 
 # Create file system image from directory content