diff --git a/src/matrix/calls/PeerCall.ts b/src/matrix/calls/PeerCall.ts
index 515e1b65..98747e40 100644
--- a/src/matrix/calls/PeerCall.ts
+++ b/src/matrix/calls/PeerCall.ts
@@ -18,24 +18,24 @@ import {ObservableMap} from "../../observable/map/ObservableMap";
 import {recursivelyAssign} from "../../utils/recursivelyAssign";
 import {AsyncQueue} from "../../utils/AsyncQueue";
 import {Disposables, IDisposable} from "../../utils/Disposables";
-import type {Room} from "../room/Room";
-import type {StateEvent} from "../storage/types";
-import type {ILogItem} from "../../logging/types";
-
-import type {TimeoutCreator, Timeout} from "../../platform/types/types";
 import {WebRTC, PeerConnection, PeerConnectionHandler, TrackSender, TrackReceiver} from "../../platform/types/WebRTC";
 import {MediaDevices, Track, AudioTrack, Stream} from "../../platform/types/MediaDevices";
-import type {LocalMedia} from "./LocalMedia";
-
 import {
     SDPStreamMetadataKey,
     SDPStreamMetadataPurpose,
     EventType,
     CallErrorCode,
 } from "./callEventTypes";
+
+import type {Room} from "../room/Room";
+import type {StateEvent} from "../storage/types";
+import type {ILogItem} from "../../logging/types";
+import type {TimeoutCreator, Timeout} from "../../platform/types/types";
+import type {LocalMedia} from "./LocalMedia";
 import type {
     MCallBase,
     MCallInvite,
+    MCallNegotiate,
     MCallAnswer,
     MCallSDPStreamMetadataChanged,
     MCallCandidates,
@@ -265,6 +265,9 @@ export class PeerCall implements IDisposable {
                 case EventType.Answer:
                     await this.handleAnswer(message.content, partyId, log);
                     break;
+                case EventType.Negotiate:
+                    await this.handleRemoteNegotiate(message.content, partyId, log);
+                    break;
                 case EventType.Candidates:
                     await this.handleRemoteIceCandidates(message.content, partyId, log);
                     break;
@@ -341,10 +344,10 @@ export class PeerCall implements IDisposable {
                 await this.sendSignallingMessage({type: EventType.Invite, content}, log);
                 this.setState(CallState.InviteSent, log);
             } else if (this._state === CallState.Connected || this._state === CallState.Connecting) {
-                log.log("would send renegotiation now but not implemented");
                 // send Negotiate message
-                //await this.sendSignallingMessage({type: EventType.Invite, content});
-                //this.setState(CallState.InviteSent);
+                content.description = content.offer;
+                delete content.offer;
+                await this.sendSignallingMessage({type: EventType.Negotiate, content}, log);
             }
         } finally {
             this.makingOffer = false;
@@ -497,6 +500,36 @@ export class PeerCall implements IDisposable {
         }
     }
 
+
+    private async handleRemoteNegotiate(content: MCallNegotiate<MCallBase>, partyId: PartyId, log: ILogItem): Promise<void> {
+        if (this._state !== CallState.Connected) {
+            log.log({l: `Ignoring renegotiate because not connected`, status: this._state});
+            return;
+        }
+
+        if (this.opponentPartyId !== partyId) {
+            log.log(`Ignoring answer: we already have an answer/reject from ${this.opponentPartyId}`);
+            return;
+        }
+
+        const sdpStreamMetadata = content[SDPStreamMetadataKey];
+        if (sdpStreamMetadata) {
+            this.updateRemoteSDPStreamMetadata(sdpStreamMetadata, log);
+        } else {
+            log.log(`Did not get any SDPStreamMetadata! Can not send/receive multiple streams`);
+        }
+
+        try {
+            await this.peerConnection.setRemoteDescription(content.description);
+        } catch (e) {
+            await log.wrap(`Failed to set remote description`, log => {
+                log.catch(e);
+                this.terminate(CallParty.Local, CallErrorCode.SetRemoteDescription, log);
+            });
+            return;
+        }
+    }
+
     private handleIceGatheringState(state: RTCIceGatheringState, log: ILogItem) {
         if (state === 'complete' && !this.sentEndOfCandidates) {
             // If we didn't get an empty-string candidate to signal the end of candidates,
diff --git a/src/matrix/calls/callEventTypes.ts b/src/matrix/calls/callEventTypes.ts
index 4726175c..449bd469 100644
--- a/src/matrix/calls/callEventTypes.ts
+++ b/src/matrix/calls/callEventTypes.ts
@@ -97,6 +97,12 @@ export type MCallInvite<Base extends MCallBase> = Base & {
     [SDPStreamMetadataKey]: SDPStreamMetadata;
 }
 
+export type MCallNegotiate<Base extends MCallBase> = Base & {
+    description: SessionDescription;
+    lifetime: number;
+    [SDPStreamMetadataKey]: SDPStreamMetadata;
+}
+
 export type MCallSDPStreamMetadataChanged<Base extends MCallBase> = Base & {
     [SDPStreamMetadataKey]: SDPStreamMetadata;
 }
@@ -213,6 +219,7 @@ export enum CallErrorCode {
 
 export type SignallingMessage<Base extends MCallBase> =
     {type: EventType.Invite, content: MCallInvite<Base>} |
+    {type: EventType.Negotiate, content: MCallNegotiate<Base>} |
     {type: EventType.Answer, content: MCallAnswer<Base>} |
     {type: EventType.SDPStreamMetadataChanged | EventType.SDPStreamMetadataChangedPrefix, content: MCallSDPStreamMetadataChanged<Base>} |
     {type: EventType.Candidates, content: MCallCandidates<Base>} |