diff --git a/migrations/000002_create_devices.up.sql b/migrations/000002_create_devices.up.sql
index 099dfbf..1bcaf18 100644
--- a/migrations/000002_create_devices.up.sql
+++ b/migrations/000002_create_devices.up.sql
@@ -4,7 +4,7 @@ CREATE TABLE devices (
     id SERIAL PRIMARY KEY,
     apns_token character varying(100) UNIQUE,
     sandbox boolean,
-    active_until integer,
-    grace_period_until integer
+    expires_at timestamp without time zone,
+    grace_period_expires_at timestamp without time zone
 );