diff --git a/app.json b/app.json
index e5c56477..749dcfdf 100644
--- a/app.json
+++ b/app.json
@@ -7,7 +7,7 @@
     "logo": "https://github.com/doccano/doccano/wiki/images/doccano.png",
     "success_url": "/",
     "env": {
-        "ADMIN_USER_NAME": {
+        "ADMIN_USERNAME": {
             "description": "The user name for the admin account."
         },
         "ADMIN_CONTACT_EMAIL": {
diff --git a/tools/heroku.sh b/tools/heroku.sh
index f6252026..8aaf7b66 100644
--- a/tools/heroku.sh
+++ b/tools/heroku.sh
@@ -2,13 +2,13 @@
 
 set -o errexit
 
-if [[ -z "${ADMIN_USER_NAME}" ]]; then echo "Missing ADMIN_USER_NAME environment variable" >&2; exit 1; fi
+if [[ -z "${ADMIN_USERNAME}" ]]; then echo "Missing ADMIN_USERNAME environment variable" >&2; exit 1; fi
 if [[ -z "${ADMIN_PASSWORD}" ]]; then echo "Missing ADMIN_PASSWORD environment variable" >&2; exit 1; fi
 if [[ -z "${ADMIN_CONTACT_EMAIL}" ]]; then echo "Missing ADMIN_CONTACT_EMAIL environment variable" >&2; exit 1; fi
 
 set -o nounset
 
 python /doccano/backend/manage.py migrate
-if [ -n "$ADMIN_USER_NAME" ]; then
-    python /doccano/backend/manage.py create_admin --noinput --username="$ADMIN_USER_NAME" --email="$ADMIN_CONTACT_EMAIL" --password="$ADMIN_PASSWORD"
+if [ -n "$ADMIN_USERNAME" ]; then
+    python /doccano/backend/manage.py create_admin --noinput --username="$ADMIN_USERNAME" --email="$ADMIN_CONTACT_EMAIL" --password="$ADMIN_PASSWORD"
 fi