diff --git a/docs/security/encrypt-data-disk-with-dm-crypt/index.md b/docs/security/encrypt-data-disk-with-dm-crypt/index.md
index a2ffcf17df4..c12f009b7f9 100644
--- a/docs/security/encrypt-data-disk-with-dm-crypt/index.md
+++ b/docs/security/encrypt-data-disk-with-dm-crypt/index.md
@@ -170,7 +170,7 @@ Follow these steps very carefully.
 
 2.  Test a scenario where the LUKS header is accidentally overwritten:
 
-        dd if=/dev/zero of=/dev/sdX bs=128 count=1
+        dd conv=notrunc if=/dev/zero of=/dev/sdX bs=128 count=1
 
 3.  Trying to open your container will now return an error: