diff --git a/SC2312.md b/SC2312.md
index 6a2d421..56c11b9 100644
--- a/SC2312.md
+++ b/SC2312.md
@@ -7,7 +7,7 @@ This is an optional suggestion enabled with `shellcheck -o check-extra-masked-re
 ```sh
 set -e
 cd "$(get_chroot_dir)/etc"
-tar xf "$config"
+tar xf "${config}"
 ```
 
 ### Correct code:
@@ -15,8 +15,8 @@ tar xf "$config"
 ```sh
 set -e
 dir="$(get_chroot_dir)"
-cd "$dir/etc"
-tar xf "$config"
+cd "${dir}/etc"
+tar xf "${config}"
 ```
 
 ### Correct code: (with correction)
@@ -24,9 +24,9 @@ tar xf "$config"
 ```sh
 set -e
 dir="$(get_chroot_dir)"
-[ -d "${dir}" ] || exit 1
-cd "$dir/etc"
-tar xf "$config"
+[[ -d "${dir}" ]] || exit 1
+cd "${dir}/etc"
+tar xf "${config}"
 ```
 
 ### Rationale: