diff --git a/baselines/dom.generated.d.ts b/baselines/dom.generated.d.ts
index def48d12b..e1f3cca27 100644
--- a/baselines/dom.generated.d.ts
+++ b/baselines/dom.generated.d.ts
@@ -12288,7 +12288,7 @@ interface RTCPeerConnection extends EventTarget {
     removeTrack(sender: RTCRtpSender): void;
     setConfiguration(configuration: RTCConfiguration): void;
     setIdentityProvider(provider: string, options?: RTCIdentityProviderOptions): void;
-    setLocalDescription(description: RTCSessionDescriptionInit): Promise<void>;
+    setLocalDescription(description?: RTCSessionDescriptionInit): Promise<void>;
     setRemoteDescription(description: RTCSessionDescriptionInit): Promise<void>;
     addEventListener<K extends keyof RTCPeerConnectionEventMap>(type: K, listener: (this: RTCPeerConnection, ev: RTCPeerConnectionEventMap[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 e022959bf..b4fc4afa4 100644
--- a/inputfiles/overridingTypes.json
+++ b/inputfiles/overridingTypes.json
@@ -1873,7 +1873,7 @@
                         "setLocalDescription": {
                             "name": "setLocalDescription",
                             "override-signatures": [
-                                "setLocalDescription(description: RTCSessionDescriptionInit): Promise<void>"
+                                "setLocalDescription(description?: RTCSessionDescriptionInit): Promise<void>"
                             ]
                         },
                         "setRemoteDescription": {