diff --git a/src/async/asyncTypes.ts b/src/async/asyncTypes.ts
index 63d6b618..4f28b5f2 100644
--- a/src/async/asyncTypes.ts
+++ b/src/async/asyncTypes.ts
@@ -17,7 +17,6 @@ export type TsonAsyncStringifier = <TValue>(
 ) => TsonAsyncStringifierIterable<TValue>;
 export type TsonAsyncIndex = TsonBranded<number, "AsyncRegistered">;
 
-type ReaderValue<T> = T | TsonStreamInterruptedError;
 export interface TsonTransformerSerializeDeserializeAsync<
 	TValue,
 	TSerializedValue,
@@ -28,13 +27,15 @@ export interface TsonTransformerSerializeDeserializeAsync<
 	 */
 	deserialize: (opts: {
 		/**
-		 * The controller for the ReadableStream, to close when we're done
+		 * Close the controller for the ReadableStream of values
 		 */
-		controller: ReadableStreamDefaultController<ReaderValue<TSerializedValue>>;
+		close: () => void;
 		/**
 		 * Reader for the ReadableStream of values
 		 */
-		reader: ReadableStreamDefaultReader<ReaderValue<TSerializedValue>>;
+		reader: ReadableStreamDefaultReader<
+			TSerializedValue | TsonStreamInterruptedError
+		>;
 	}) => TValue;
 
 	/**
diff --git a/src/async/deserializeAsync.ts b/src/async/deserializeAsync.ts
index ec14bfa2..0f298b4e 100644
--- a/src/async/deserializeAsync.ts
+++ b/src/async/deserializeAsync.ts
@@ -66,19 +66,24 @@ export function createTsonParseAsyncInner(opts: TsonAsyncOptions) {
 
 					const idx = serializedValue as TsonAsyncIndex;
 
+					let controller: ReadableStreamDefaultController<unknown> =
+						null as unknown as ReadableStreamDefaultController<unknown>;
 					const readable = new ReadableStream<unknown>({
 						start(c) {
-							cache.set(idx, c);
+							controller = c;
 						},
 					});
+					// the `start` method is called "immediately when the object is constructed"
+					// [MDN](http://developer.mozilla.org/en-US/docs/Web/API/ReadableStream/ReadableStream)
+					// so we're guaranteed that the controller is set in the cache
+					assert(controller, "Controller not set - this is a bug");
+
+					cache.set(idx, controller);
 
 					return transformer.deserialize({
-						get controller() {
-							// the `start` method is called "immediately when the object is constructed"
-							// [MDN](http://developer.mozilla.org/en-US/docs/Web/API/ReadableStream/ReadableStream)
-							// so we're guaranteed that the controller is set in the cache
-							// eslint-disable-next-line @typescript-eslint/no-non-null-assertion
-							return cache.get(idx)!;
+						close() {
+							controller.close();
+							cache.delete(idx);
 						},
 						reader: readable.getReader(),
 					});
@@ -197,11 +202,7 @@ export function createTsonParseAsyncInner(opts: TsonAsyncOptions) {
 
 					// enqueue the error to all the streams
 					for (const controller of cache.values()) {
-						try {
-							controller.enqueue(err);
-						} catch {
-							// ignore if the controller is closed
-						}
+						controller.enqueue(err);
 					}
 
 					opts.onStreamError?.(err);
diff --git a/src/async/handlers/tsonAsyncIterable.ts b/src/async/handlers/tsonAsyncIterable.ts
index ce58840e..46a74d2e 100644
--- a/src/async/handlers/tsonAsyncIterable.ts
+++ b/src/async/handlers/tsonAsyncIterable.ts
@@ -36,12 +36,10 @@ export const tsonAsyncIterator: TsonAsyncType<
 
 				switch (value[0]) {
 					case ITERATOR_DONE: {
-						opts.controller.close();
 						return;
 					}
 
 					case ITERATOR_ERROR: {
-						opts.controller.close();
 						throw TsonPromiseRejectionError.from(value[1]);
 					}
 
@@ -51,6 +49,8 @@ export const tsonAsyncIterator: TsonAsyncType<
 					}
 				}
 			}
+
+			opts.close();
 		})();
 	},
 	key: "AsyncIterable",
diff --git a/src/async/handlers/tsonPromise.ts b/src/async/handlers/tsonPromise.ts
index ad650d0b..e6f60e6a 100644
--- a/src/async/handlers/tsonPromise.ts
+++ b/src/async/handlers/tsonPromise.ts
@@ -28,7 +28,7 @@ export const tsonPromise: TsonAsyncType<MyPromise, SerializedPromiseValue> = {
 		const promise = new Promise((resolve, reject) => {
 			async function _handle() {
 				const next = await opts.reader.read();
-				opts.controller.close();
+				opts.close();
 
 				if (next.done) {
 					throw new TsonPromiseRejectionError(