diff --git a/jecs.d.ts b/jecs.d.ts
index 965a7bf..54deed3 100755
--- a/jecs.d.ts
+++ b/jecs.d.ts
@@ -247,6 +247,10 @@ export class World {
 	 * @returns A Query object to iterate over results.
 	 */
 	query<T extends Id[]>(...components: T): Query<InferComponents<T>>;
+
+	added<T>(component: Entity<T>, listener: (e: Entity, id: Id<T>, value: T) => void): () => void
+	changed<T>(component: Entity<T>, listener: (e: Entity, id: Id<T>) => void): () => void
+	removed<T>(component: Entity<T>, listener: (e: Entity, id: Id<T>, value: T) => void): () => void
 }
 
 export function world(): World;
diff --git a/jecs.luau b/jecs.luau
index 228f59b..37c550a 100755
--- a/jecs.luau
+++ b/jecs.luau
@@ -150,9 +150,9 @@ export type World = {
 
 	observable: Map<Id, Map<Id, { Observer }>>,
 
-	added: <T>(World, Id<T>, <e>(e: Entity<e>, id: Id<T>, value: T?) -> ()) -> () -> (),
-	removed: <T>(World, Id<T>, (e: Entity, id: Id<T>) -> ()) -> () -> (),
-	changed:  <T>(World, Id<T>, <e>(e: Entity<e>, id: Id<T>, value: T) -> ()) -> () -> (),
+	added: <T>(World, Entity<T>, <e>(e: Entity<e>, id: Id<T>, value: T?) -> ()) -> () -> (),
+	removed: <T>(World, Entity<T>, (e: Entity, id: Id<T>) -> ()) -> () -> (),
+	changed:  <T>(World, Entity<T>, <e>(e: Entity<e>, id: Id<T>, value: T) -> ()) -> () -> (),
 
 	--- Enforce a check on entities to be created within desired range
 	range: (self: World, range_begin: number, range_end: number?) -> (),