diff --git a/README.md b/README.md
index aa43cf8..47ed075 100644
--- a/README.md
+++ b/README.md
@@ -10,6 +10,7 @@ You can adjust the default configuration by placing a file `oauth-mock-server.js
 
 ```json
 {
+  "port": 5000,
   "realm": "my-project",
   "users": [
     {
@@ -30,6 +31,7 @@ You can adjust the default configuration by placing a file `oauth-mock-server.js
       "email": "her@bert.de",
       "name": "Herbert"
     }
-  ]
+  ],
+  "tokenExpiresIn": 86400 // 24 hours in seconds
 }
 ```
diff --git a/src/config.ts b/src/config.ts
index 55e9932..6a78696 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -10,12 +10,15 @@ export type ConfigUser = {
 };
 
 export type Config = {
+  port: number;
   realm: string;
   users: ConfigUser[];
+  tokenExpiresIn: number;
 };
 
 export function getConfig(): Config {
   const defaultConfig = <Config>{
+    port: 5000,
     realm: process.env.REALM || 'my-project',
     users: [
       {
@@ -37,6 +40,7 @@ export function getConfig(): Config {
         name: 'Herbert',
       },
     ],
+    tokenExpiresIn: 24 * 60 * 60, // 24 hours in seconds
   };
 
   const configPath = path.join(cwd(), 'oauth-mock-server.json');
diff --git a/src/index.ts b/src/index.ts
index 0a47e0a..285ca07 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -122,13 +122,13 @@ server.post(`/auth/realms/${config.realm}/protocol/openid-connect/token`, async
     aud: config.realm,
   };
 
-  const accessToken = jwt.sign(payload, jwtSecret, { expiresIn: '1h' });
+  const accessToken = jwt.sign(payload, jwtSecret, { expiresIn: config.tokenExpiresIn });
 
   return {
     access_token: accessToken,
     token_type: 'Bearer',
     id_token: accessToken,
-    expires_in: 3600,
+    expires_in: config.tokenExpiresIn,
   };
 });
 
@@ -146,11 +146,10 @@ server.get(`/auth/realms/${config.realm}/protocol/openid-connect/logout`, async
 });
 
 async function start() {
-  const port = 5000; // TODO: support custom port
   try {
     // eslint-disable-next-line no-console
-    console.log(`Starting server http://localhost:${port} ...`);
-    await server.listen({ port, host: '0.0.0.0' });
+    console.log(`Starting server http://localhost:${config.port} ...`);
+    await server.listen({ port: config.port, host: '0.0.0.0' });
   } catch (err) {
     server.log.error(err);
     process.exit(1);