diff --git a/migrations/20190725172940-settings-migrate-cloudron-conf.js b/migrations/20190725172940-settings-migrate-cloudron-conf.js
index 6ba2b22d9..c4cc212b7 100644
--- a/migrations/20190725172940-settings-migrate-cloudron-conf.js
+++ b/migrations/20190725172940-settings-migrate-cloudron-conf.js
@@ -14,11 +14,12 @@ exports.up = function(db, callback) {
 
     async.series([
         db.runSql.bind(db, 'START TRANSACTION;'),
-        db.runSql.bind(db, 'INSERT settings (name, value) VALUES(?, ?)', [ 'api_server_origin', config.apiServerOrigin ]),
-        db.runSql.bind(db, 'INSERT settings (name, value) VALUES(?, ?)', [ 'web_server_origin', config.webServerOrigin ]),
-        db.runSql.bind(db, 'INSERT settings (name, value) VALUES(?, ?)', [ 'admin_domain', config.adminDomain ]),
-        db.runSql.bind(db, 'INSERT settings (name, value) VALUES(?, ?)', [ 'admin_fqdn', config.adminFqdn ]),
-        db.runSql.bind(db, 'INSERT settings (name, value) VALUES(?, ?)', [ 'demo', config.isDemo ]),
+        // we use replace instead of insert because the cloudron-setup adds api/web_server_origin even for legacy setups
+        db.runSql.bind(db, 'REPLACE INTO settings (name, value) VALUES(?, ?)', [ 'api_server_origin', config.apiServerOrigin ]),
+        db.runSql.bind(db, 'REPLACE INTO settings (name, value) VALUES(?, ?)', [ 'web_server_origin', config.webServerOrigin ]),
+        db.runSql.bind(db, 'REPLACE INTO settings (name, value) VALUES(?, ?)', [ 'admin_domain', config.adminDomain ]),
+        db.runSql.bind(db, 'REPLACE INTO settings (name, value) VALUES(?, ?)', [ 'admin_fqdn', config.adminFqdn ]),
+        db.runSql.bind(db, 'REPLACE INTO settings (name, value) VALUES(?, ?)', [ 'demo', config.isDemo ]),
         db.runSql.bind(db, 'COMMIT')
     ], callback);
 };
diff --git a/scripts/cloudron-setup b/scripts/cloudron-setup
index abdd2b894..22b16d07d 100755
--- a/scripts/cloudron-setup
+++ b/scripts/cloudron-setup
@@ -200,11 +200,21 @@ if [[ "${initBaseImage}" == "true" ]]; then
     echo ""
 fi
 
-# NOTE: this install script only supports 4.2 and above
+# NOTE: this install script only supports 3.x and above
 echo "=> Installing version ${version} (this takes some time) ..."
 mkdir -p /etc/cloudron
+# this file is used >= 4.2
 echo "${provider}" > /etc/cloudron/PROVIDER
 
+# this file is unused <= 4.2 and exists to make legacy installations work. the start script will remove this file anyway
+cat > "/etc/cloudron/cloudron.conf" <<CONF_END
+{
+    "apiServerOrigin": "${apiServerOrigin}",
+    "webServerOrigin": "${webServerOrigin}",
+    "provider": "${provider}"
+}
+CONF_END
+
 [[ -n "${license}" ]] && echo -n "$license" > /etc/cloudron/LICENSE
 
 if ! /bin/bash "${box_src_tmp_dir}/scripts/installer.sh" &>> "${LOG_FILE}"; then
@@ -212,6 +222,7 @@ if ! /bin/bash "${box_src_tmp_dir}/scripts/installer.sh" &>> "${LOG_FILE}"; then
     exit 1
 fi
 
+# only needed for >= 4.2
 mysql -uroot -ppassword -e "REPLACE INTO box.settings (name, value) VALUES ('api_server_origin', '${apiServerOrigin}');" 2>/dev/null
 mysql -uroot -ppassword -e "REPLACE INTO box.settings (name, value) VALUES ('web_server_origin', '${webServerOrigin}');" 2>/dev/null