diff --git a/options.go b/options.go
index c5f9daf..7ef516e 100644
--- a/options.go
+++ b/options.go
@@ -25,9 +25,10 @@ type Options struct {
 	DBPath string `env:"DB_PATH" default:"eve-pi.db" description:"Database file path"`
 	Port   string `env:"HTTP_SERVER_PORT" default:"3000" description:"HTTP server port"`
 
-	ClientID    string   `env:"ESI_CLIENT_ID" description:"EVE SSO client ID"`
-	RedirectURI string   `env:"ESI_REDIRECT_URI" default:"http://localhost:3000/callback" description:"EVE SSO redirect URI"`
-	Scopes      []string `env:"ESI_SCOPES" default:"esi-planets.manage_planets.v1" description:"EVE SSO scopes (space-separated)"`
+	ClientID      string   `env:"ESI_CLIENT_ID" description:"EVE SSO client ID"`
+	RedirectURI   string   `env:"ESI_REDIRECT_URI" default:"http://localhost:3000/callback" description:"EVE SSO redirect URI"`
+	Scopes        []string `env:"ESI_SCOPES" default:"esi-planets.manage_planets.v1" description:"EVE SSO scopes (space-separated)"`
+	CacheValidity string   `env:"ESI_CACHE_VALIDITY" default:"PT20M" description:"ESI cache validity in duration (e.g. PT20M for 20 minutes)"`
 
 	WebhookURL   string `env:"WEBHOOK_URL" description:"Webhook URL for notifications"`
 	WebhookEmail string `env:"WEBHOOK_EMAIL" description:"Webhook authentication email"`