diff --git a/packages/reffuse/src/types/SubscriptionSubRef.ts b/packages/reffuse/src/types/SubscriptionSubRef.ts
index 15baba7..4ea615d 100644
--- a/packages/reffuse/src/types/SubscriptionSubRef.ts
+++ b/packages/reffuse/src/types/SubscriptionSubRef.ts
@@ -3,6 +3,7 @@ import * as PropertyPath from "./PropertyPath.js"
 
 
 export const SubscriptionSubRefTypeId: unique symbol = Symbol.for("reffuse/types/SubscriptionSubRef")
+export type SubscriptionSubRefTypeId = typeof SubscriptionSubRefTypeId
 
 export interface SubscriptionSubRef<in out A, in out B> extends SubscriptionSubRef.Variance<A, B>, SubscriptionRef.SubscriptionRef<A> {
     readonly parent: SubscriptionRef.SubscriptionRef<B>