diff --git a/src/config.ts b/src/config.ts
index 0be75cc..367981b 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -22,6 +22,8 @@ const envs = {
 
 	// header where user info token is stored to request auth proxy
 	USERINFO_HEADER: env.get('USERINFO_HEADER').default("X-Userinfo-Token").asString(),
+	// header when user info token expires (seconds after 01/01/1970)
+	EXPIRE_HEADER: env.get('EXPIRE_HEADER').default("X-Userinfo-Expire").asString(),
 	// base url to init a logout or request user info
 	AUTH_PROXY_URL: env.get('AUTH_PROXY_URL').asString() || undefined,
 	// override AUTH_PROXY_URL to request user info