diff --git a/jecs.luau b/jecs.luau
index e5faf96..dc60a9a 100644
--- a/jecs.luau
+++ b/jecs.luau
@@ -2525,8 +2525,8 @@ end
 
 World.new = world_new
 
-export type Entity<T = any> = { __T: T }
-export type Id<T = any> = { __T: T }
+export type Entity<T = any> = number | { __T: T }
+export type Id<T = any> = number | { __T: T }
 export type Pair<P, O> = Id<P>
 type ecs_id_t<T=unknown> = Id<T> | Pair<T, "Tag"> | Pair<"Tag", T>
 export type Item<T...> = (self: Query<T...>) -> (Entity, T...)
@@ -2601,10 +2601,10 @@ export type World = {
 		& (<T, a, b, c, d>(World, Entity<T>, Id<a>, Id<b>, Id<c>, Id<d>) -> (a?, b?, c?, d?)),
 
 	--- Returns whether the entity has the ID.
-	has: (<T>(World, Entity<T>, Id) -> boolean)
-		& (<T>(World, Entity<T>, Id, Id) -> boolean)
-		& (<T>(World, Entity<T>, Id, Id, Id) -> boolean)
-		& <T>(World, Entity<T>, Id, Id, Id, Id) -> boolean,
+	has: (<T, a>(World, Entity<T>, Id<a>) -> boolean)
+		& (<T, a, b >(World, Entity<T>, Id<a>, Id<a>) -> boolean)
+		& (<T, a, b, c>(World, Entity<T>, Id<a>, Id<b>, Id<c>) -> boolean)
+		& <T, a, b, c, d>(World, Entity<T>, Id<a>, Id<b>, Id<c>, Id<d>) -> boolean,
 
 	--- Get parent (target of ChildOf relationship) for entity. If there is no ChildOf relationship pair, it will return nil.
 	parent: <T>(self: World, entity: Entity<T>) -> Entity,
diff --git a/test/addons/observers.luau b/test/addons/observers.luau
index 0a363cc..182a3ea 100644
--- a/test/addons/observers.luau
+++ b/test/addons/observers.luau
@@ -7,6 +7,17 @@ local observers_add = require("@addons/observers")
 TEST("addons/observers", function()
 	local world = observers_add(jecs.world())
 
+	local Test = world:component() :: jecs.Id<number>
+	type Q<T...> = () -> (jecs.Entity, T...)
+	local query:
+		(<A>(jecs.World, jecs.Id<A>) -> Q<A>)
+		& (<A, B>(jecs.World, jecs.Id<A>, jecs.Id<B>) -> Q<A, B>)
+		& (<A, B, C>(jecs.World, jecs.Id<A>, jecs.Id<B>, jecs.Id<C>) -> Q<A, B, C>)
+		= 1 :: never
+	for e, a in query(world, Test) do
+
+	end
+
 	do CASE "Should work even if set after the component has been used"
 		local A = world:component()
 
diff --git a/test/tests.luau b/test/tests.luau
index 9ce5023..d5e578f 100644
--- a/test/tests.luau
+++ b/test/tests.luau
@@ -661,7 +661,7 @@ TEST("world:range()", function()
 	do CASE "under range start"
 		local world = jecs.world()
 		world:range(400, 1000)
-		local id = world:entity()
+		local id = world:entity() :: number
 		local e = world:entity(id + 5)
 		CHECK(e == id + 5)
 		CHECK(world:contains(e))
@@ -669,7 +669,7 @@ TEST("world:range()", function()
 		CHECK(world:contains(e2))
 		world:delete(e2)
 		CHECK(not world:contains(e2))
-		local e2v1 = world:entity(399)
+		local e2v1 = world:entity(399) :: number
 		CHECK(world:contains(e2v1))
 		CHECK(ECS_ID(e2v1) == 399)
 		CHECK(ECS_GENERATION(e2v1) == 0)
@@ -682,13 +682,13 @@ TEST("world:range()", function()
 		CHECK(world:contains(e2))
 		world:delete(e2)
 		CHECK(not world:contains(e2))
-		local e2v1 = world:entity(405)
+		local e2v1 = world:entity(405) :: number
 		CHECK(world:contains(e2v1))
 		CHECK(ECS_ID(e2v1) == 405)
 		CHECK(ECS_GENERATION(e2v1) == 0)
 
 		world:delete(e2v1)
-		local e2v2 = world:entity(e2v1)
+		local e2v2 = world:entity(e2v1) :: number
 		CHECK(ECS_ID(e2v2) == 405)
 		CHECK(ECS_GENERATION(e2v2) == 0)
 	end
@@ -697,7 +697,7 @@ end)
 TEST("world:entity()", function()
 	do CASE "desired id"
 		local world = jecs.world()
-		local id = world:entity()
+		local id = world:entity() :: number
 		local e = world:entity(id + 5)
 		CHECK(e == id + 5)
 		CHECK(world:contains(e))
@@ -767,11 +767,11 @@ TEST("world:entity()", function()
 			local e = world:entity()
 			world:delete(e)
 		end
-		local e = world:entity() :: any
+		local e = world:entity() :: number
 		CHECK(ECS_ID(e) == pin)
 		CHECK(ECS_GENERATION(e) == 2^16-1)
 		world:delete(e)
-		e = world:entity()
+		e = world:entity() :: number
 		CHECK(ECS_ID(e) == pin)
 		CHECK(ECS_GENERATION(e) == 0)
 	end