diff --git a/baselines/dom.generated.d.ts b/baselines/dom.generated.d.ts
index a689cbbd5..fd9674fd5 100644
--- a/baselines/dom.generated.d.ts
+++ b/baselines/dom.generated.d.ts
@@ -17484,7 +17484,8 @@ 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/baselines/webworker.generated.d.ts b/baselines/webworker.generated.d.ts
index 5416485fa..1e2c9452b 100644
--- a/baselines/webworker.generated.d.ts
+++ b/baselines/webworker.generated.d.ts
@@ -4299,7 +4299,8 @@ 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/inputfiles/overridingTypes.json b/inputfiles/overridingTypes.json
index 7d58a9e03..fc5bfe508 100644
--- a/inputfiles/overridingTypes.json
+++ b/inputfiles/overridingTypes.json
@@ -2312,8 +2312,10 @@
                     "method": {
                         "postMessage": {
                             "deprecated": 0,
+                            "name": "postMessage",
                             "override-signatures": [
-                                "postMessage(message: any, transfer?: Transferable[]): void"
+                                "postMessage(message: any, transfer: Transferable[]): void",
+                                "postMessage(message: any, options?: PostMessageOptions): void"
                             ]
                         }
                     }
diff --git a/src/emitter.ts b/src/emitter.ts
index cc321cfa3..de8846eec 100644
--- a/src/emitter.ts
+++ b/src/emitter.ts
@@ -689,7 +689,7 @@ export function emitWebIdl(webidl: Browser.WebIdl, flavor: Flavor) {
 
     /// Emit the properties and methods of a given interface
     function emitMembers(prefix: string, emitScope: EmitScope, i: Browser.Interface) {
-        const conflictedMembers = extendConflictsBaseTypes[i.name] ? extendConflictsBaseTypes[i.name].memberNames : new Set();
+        const conflictedMembers = extendConflictsBaseTypes[i.name] ? extendConflictsBaseTypes[i.name].memberNames : new Set<string>();
         emitProperties(prefix, emitScope, i);
         const methodPrefix = prefix.startsWith("declare var") ? "declare function " : "";
         emitMethods(methodPrefix, emitScope, i, conflictedMembers);
diff --git a/src/widlprocess.ts b/src/widlprocess.ts
index 2f7b7f3f7..dda75c7af 100644
--- a/src/widlprocess.ts
+++ b/src/widlprocess.ts
@@ -197,7 +197,7 @@ function convertOperation(operation: webidl2.OperationMemberType, inheritedExpos
         throw new Error("Unexpected anonymous operation");
     }
     return {
-        name: operation.name,
+        name: operation.name || undefined,
         signature: [{
             ...convertIdlType(operation.idlType),
             param: operation.arguments.map(convertArgument)