diff --git a/cd-bootstrap.sh b/cd-bootstrap.sh
index 3fc156a..dbab7b6 100755
--- a/cd-bootstrap.sh
+++ b/cd-bootstrap.sh
@@ -1,5 +1,6 @@
 KEY_ALGORITHM='ed25519'
-KEY_PATH=".ssh/id_${KEY_ALGORITHM}"
+KEY_DIRECTORY='.ssh'
+KEY_PATH="${KEY_DIRECTORY}/id_${KEY_ALGORITHM}"
 KEY_PUBLIC='AAAAC3NzaC1lZDI1NTE5AAAAIPHCNcgHlQoiNTXfnUZYvHz9OZwYsmBCrSSV7a7Zche5'
 PACKAGES=(
 'python3'
@@ -9,8 +10,9 @@ PACKAGES=(
 SERVER="$(basename ${GITHUB_SERVER_URL})"
 
 # ssh
-cd
-mkdir '.ssh' \
+cd \
+|| exit
+mkdir "${KEY_DIRECTORY}" \
 || exit
 echo "${CD}" > "${KEY_PATH}" \
 || exit
@@ -18,7 +20,7 @@ unset CD
 chmod '400' "${KEY_PATH}" \
 || exit
 echo "${SERVER} ssh-${KEY_ALGORITHM} ${KEY_PUBLIC}" \
-> '.ssh/known_hosts' \
+> "${KEY_DIRECTORY}/known_hosts" \
 || exit
 
 # packages