diff --git a/src/lib/dom.generated.d.ts b/src/lib/dom.generated.d.ts
index b1daca71fed54..18f38b5356053 100644
--- a/src/lib/dom.generated.d.ts
+++ b/src/lib/dom.generated.d.ts
@@ -17328,7 +17328,8 @@ interface WorkerEventMap extends AbstractWorkerEventMap {
 /** An interface of the Web Workers API represents a background task that can be easily created and can send messages back to its creator. Creating a worker is as simple as calling the Worker() constructor and specifying a script to be run in the worker thread. */
 interface Worker extends EventTarget, AbstractWorker {
     onmessage: ((this: Worker, ev: MessageEvent) => any) | null;
-    postMessage(message: any, transfer?: Transferable[]): void;
+    postMessage(message: any, transfer: Transferable[]): void;
+    postMessage(message: any, options?: PostMessageOptions): void;
     terminate(): void;
     addEventListener<K extends keyof WorkerEventMap>(type: K, listener: (this: Worker, ev: WorkerEventMap[K]) => any, options?: boolean | AddEventListenerOptions): void;
     addEventListener(type: string, listener: EventListenerOrEventListenerObject, options?: boolean | AddEventListenerOptions): void;
diff --git a/src/lib/webworker.generated.d.ts b/src/lib/webworker.generated.d.ts
index cc35615d12914..de98e9537aa94 100644
--- a/src/lib/webworker.generated.d.ts
+++ b/src/lib/webworker.generated.d.ts
@@ -4231,7 +4231,8 @@ interface WorkerEventMap extends AbstractWorkerEventMap {
 /** An interface of the Web Workers API represents a background task that can be easily created and can send messages back to its creator. Creating a worker is as simple as calling the Worker() constructor and specifying a script to be run in the worker thread. */
 interface Worker extends EventTarget, AbstractWorker {
     onmessage: ((this: Worker, ev: MessageEvent) => any) | null;
-    postMessage(message: any, transfer?: Transferable[]): void;
+    postMessage(message: any, transfer: Transferable[]): void;
+    postMessage(message: any, options?: PostMessageOptions): void;
     terminate(): void;
     addEventListener<K extends keyof WorkerEventMap>(type: K, listener: (this: Worker, ev: WorkerEventMap[K]) => any, options?: boolean | AddEventListenerOptions): void;
     addEventListener(type: string, listener: EventListenerOrEventListenerObject, options?: boolean | AddEventListenerOptions): void;
diff --git a/tests/baselines/reference/intersectionsOfLargeUnions2.errors.txt b/tests/baselines/reference/intersectionsOfLargeUnions2.errors.txt
index a8d4f797fea9d..bad3705abc0b6 100644
--- a/tests/baselines/reference/intersectionsOfLargeUnions2.errors.txt
+++ b/tests/baselines/reference/intersectionsOfLargeUnions2.errors.txt
@@ -10,7 +10,7 @@ tests/cases/compiler/intersectionsOfLargeUnions2.ts(31,15): error TS2536: Type '
         interface ElementTagNameMap {
                   ~~~~~~~~~~~~~~~~~
 !!! error TS2300: Duplicate identifier 'ElementTagNameMap'.
-!!! related TS6203 /.ts/lib.dom.d.ts:18109:6: 'ElementTagNameMap' was also declared here.
+!!! related TS6203 /.ts/lib.dom.d.ts:18110:6: 'ElementTagNameMap' was also declared here.
             [index: number]: HTMLElement
         }