diff --git a/db.go b/db.go
index 611afd0..b3a2993 100644
--- a/db.go
+++ b/db.go
@@ -225,6 +225,8 @@ func OpenDatabase(connString string) (*DB, error) {
 	}
 	// Add token_expiry column if missing (used by OAuth library)
 	pool.Exec(ctx, "ALTER TABLE oauth_sessions ADD COLUMN IF NOT EXISTS token_expiry TIMESTAMP")
+	// Make access_token nullable (session created before tokens obtained)
+	pool.Exec(ctx, "ALTER TABLE oauth_sessions ALTER COLUMN access_token DROP NOT NULL")
 
 	// Migration: rename feed columns for consistent terminology
 	// last_crawled_at -> last_checked_at (feed_check = checking feeds for new items)