diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7053f174..d5c194bc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,8 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/).
 
 ### Added
 
+- 追加特性のCategoryCodeSetに座席を追加
+
 ### Changed
 
 - 座席にmaximumAttendeeCapacityを拡張
diff --git a/src/additionalProperty.ts b/src/additionalProperty.ts
index e8017217..05188f80 100644
--- a/src/additionalProperty.ts
+++ b/src/additionalProperty.ts
@@ -24,6 +24,7 @@ export type CategorySetIdentifier = CategoryCodeType
     | OfferType.Offer
     | OrderType.Order
     | PlaceType.MovieTheater
+    | PlaceType.Seat
     | SellerType;
 /**
  * {@link https://schema.org/CategoryCodeSet}