2 files changed, 5 insertions, 5 deletions
diff --git a/src/js/builtins/ReadableStreamDefaultReader.ts b/src/js/builtins/ReadableStreamDefaultReader.ts
index ecd553ed5..70c6df8c3 100644
--- a/src/js/builtins/ReadableStreamDefaultReader.ts
+++ b/src/js/builtins/ReadableStreamDefaultReader.ts
@@ -43,7 +43,7 @@ export function cancel(this, reason) {
   return $readableStreamReaderGenericCancel(this, reason);
 }
 
-export function readMany(this) {
+export function readMany(this: ReadableStreamDefaultReader): ReadableStreamDefaultReadManyResult<any> {
   if (!$isReadableStreamDefaultReader(this))
     throw new TypeError("ReadableStreamDefaultReader.readMany() should not be called directly");
 
@@ -75,7 +75,7 @@ export function readMany(this) {
   var length = values.length;
 
   if (length > 0) {
-    var outValues = $newArrayWithSize(length);
+    var outValues = $newArrayWithSize<T>(length);
     if ($isReadableByteStreamController(controller)) {
       {
         const buf = values[0];
diff --git a/src/js/builtins/builtins.d.ts b/src/js/builtins/builtins.d.ts
index 449c9c128..2de8d8206 100644
--- a/src/js/builtins/builtins.d.ts
+++ b/src/js/builtins/builtins.d.ts
@@ -433,9 +433,9 @@ declare interface ArrayBufferConstructor<T> extends ClassWithIntrinsics<ArrayBuf
 declare interface PromiseConstructor<T> extends ClassWithIntrinsics<PromiseConstructor<T>> {}
 
 declare interface UnderlyingSource {
-  $lazy: boolean;
-  $bunNativeType: number;
-  $bunNativePtr: number;
+  $lazy?: boolean;
+  $bunNativeType?: number;
+  $bunNativePtr?: number;
   autoAllocateChunkSize?: number;
 }