diff --git a/jecs.d.ts b/jecs.d.ts
index 0b4a932..65b6728 100755
--- a/jecs.d.ts
+++ b/jecs.d.ts
@@ -236,6 +236,12 @@ export class World {
 	 */
 	contains(entity: Entity): boolean;
 
+	/**
+	 * Checks if an entity exists in the world.
+	 * @param entity The entity to verify.
+	 */
+	contains(entity: number): entity is Entity;
+
 	/**
 	 * Checks if an entity with the given ID is currently alive, ignoring its generation.
 	 * @param entity The entity to verify.