diff --git a/README.md b/README.md
index a38e56d..6c1bfba 100644
--- a/README.md
+++ b/README.md
@@ -346,10 +346,10 @@ This section provides integration guides for configuring the UniFi Voucher Site
 
 Below is a list of tested Identity Providers (IdPs) with detailed integration instructions:
 
-- [Keycloak Integration](.docs/oidc/keycloak/README.md)
-- [Authentik Integration](.docs/oidc/authentik/README.md)
+- [Keycloak](.docs/oidc/keycloak/README.md)
+- [Authentik](.docs/oidc/authentik/README.md)
 - [UniFi Identity Enterprise (UID)](.docs/oidc/uid/README.md)
-- [ZITADEL Integration](.docs/oidc/zitadel/README.md)
+- [ZITADEL](.docs/oidc/zitadel/README.md)
 
 > Integrated with an IdP that is not on the list? Feel free to create a guide for others and contribute it to the project
 
diff --git a/modules/config.js b/modules/config.js
index 7adf02e..bd8aeb9 100644
--- a/modules/config.js
+++ b/modules/config.js
@@ -7,16 +7,19 @@ const fs = require('fs');
  * Get an option from external config (Home Assistant / Local Development)
  *
  * @param option
+ * @return {*|null}
  */
 module.exports = (option) => {
     // Check if Home Assistant config exists
     if (fs.existsSync('/data/options.json')) {
-        return JSON.parse(fs.readFileSync('/data/options.json', 'utf-8'))[option];
+        const data = JSON.parse(fs.readFileSync('/data/options.json', 'utf-8'));
+        return typeof data[option] !== 'undefined' ? data[option] : null;
     }
 
     // Check if Local (Development) config exists
     if (fs.existsSync(`${__dirname}/../.options.json`)) {
-        return JSON.parse(fs.readFileSync(`${__dirname}/../.options.json`, 'utf-8'))[option];
+        const data = JSON.parse(fs.readFileSync(`${__dirname}/../.options.json`, 'utf-8'));
+        return typeof data[option] !== 'undefined' ? data[option] : null;
     }
 
     return null;
diff --git a/modules/variables.js b/modules/variables.js
index 83bf94c..384d31b 100644
--- a/modules/variables.js
+++ b/modules/variables.js
@@ -15,10 +15,10 @@ module.exports = {
     unifiSsid: config('unifi_ssid') || process.env.UNIFI_SSID || '',
     unifiSsidPassword: config('unifi_ssid_password') || process.env.UNIFI_SSID_PASSWORD || '',
     voucherTypes: config('voucher_types') || process.env.VOUCHER_TYPES || '480,1,,,;',
-    voucherCustom: typeof config('voucher_custom') !== 'undefined' ? config('voucher_custom') : typeof process.env.VOUCHER_CUSTOM !== 'undefined' ? process.env.VOUCHER_CUSTOM !== 'false' : true,
-    serviceWeb: typeof config('service_web') !== 'undefined' ? config('service_web') : typeof process.env.SERVICE_WEB !== 'undefined' ? process.env.SERVICE_WEB !== 'false' : true,
+    voucherCustom: config('voucher_custom') !== null ? config('voucher_custom') : process.env.VOUCHER_CUSTOM ? process.env.VOUCHER_CUSTOM !== 'false' : true,
+    serviceWeb: config('service_web') !== null ? config('service_web') : process.env.SERVICE_WEB ? process.env.SERVICE_WEB !== 'false' : true,
     serviceApi: config('service_api') || (process.env.SERVICE_API === 'true') || false,
-    authInternalEnabled: typeof config('auth_internal_enabled') !== 'undefined' ? config('auth_internal_enabled') : typeof process.env.AUTH_INTERNAL_ENABLED !== 'undefined' ? process.env.AUTH_INTERNAL_ENABLED !== 'false' : true,
+    authInternalEnabled: config('auth_internal_enabled') !== null ? config('auth_internal_enabled') : process.env.AUTH_INTERNAL_ENABLED ? process.env.AUTH_INTERNAL_ENABLED !== 'false' : true,
     authInternalPassword: config('auth_internal_password') || process.env.AUTH_INTERNAL_PASSWORD || '0000',
     authToken: config('auth_internal_bearer_token') || process.env.AUTH_INTERNAL_BEARER_TOKEN || '00000000-0000-0000-0000-000000000000',
     authOidcEnabled: config('auth_oidc_enabled') || (process.env.AUTH_OIDC_ENABLED === 'true') || false,