diff --git a/spec/integ/matrix-client-event-timeline.spec.ts b/spec/integ/matrix-client-event-timeline.spec.ts
index fe7393bfd..4bf36baa8 100644
--- a/spec/integ/matrix-client-event-timeline.spec.ts
+++ b/spec/integ/matrix-client-event-timeline.spec.ts
@@ -611,7 +611,12 @@ describe("MatrixClient event timelines", function() {
                     return THREAD_ROOT;
                 });
 
-            httpBackend.when("GET", "/rooms/!foo%3Abar/relations/" +
+            httpBackend.when("GET", "/rooms/!foo%3Abar/event/" + encodeURIComponent(THREAD_ROOT.event_id!))
+                .respond(200, function() {
+                    return THREAD_ROOT;
+                });
+
+            httpBackend.when("GET", "/_matrix/client/v1/rooms/!foo%3Abar/relations/" +
                 encodeURIComponent(THREAD_ROOT.event_id!) + "/" +
                 encodeURIComponent(THREAD_RELATION_TYPE.name) + "?dir=b&limit=1")
                 .respond(200, function() {
@@ -650,7 +655,6 @@ describe("MatrixClient event timelines", function() {
                 encodeURIComponent(THREAD_RELATION_TYPE.name) + "?dir=b&limit=1")
                 .respond(200, function() {
                     return {
-                        original_event: THREAD_ROOT,
                         chunk: [THREAD_REPLY],
                         // no next batch as this is the oldest end of the timeline
                     };
@@ -660,11 +664,17 @@ describe("MatrixClient event timelines", function() {
             await httpBackend.flushAllExpected();
             const timelineSet = thread.timelineSet;
 
-            const timelinePromise = client.getEventTimeline(timelineSet, THREAD_REPLY.event_id!);
-            const timeline = await timelinePromise;
+            httpBackend.when("GET", "/rooms/!foo%3Abar/event/" + encodeURIComponent(THREAD_ROOT.event_id!))
+                .respond(200, function() {
+                    return THREAD_ROOT;
+                });
 
-            expect(timeline!.getEvents().find(e => e.getId() === THREAD_ROOT.event_id!)).toBeTruthy();
-            expect(timeline!.getEvents().find(e => e.getId() === THREAD_REPLY.event_id!)).toBeTruthy();
+            const timelinePromise = client.getEventTimeline(timelineSet, THREAD_REPLY.event_id!);
+            const [timeline] = await Promise.all([timelinePromise, httpBackend.flushAllExpected()]);
+
+            const eventIds = timeline!.getEvents().map(it => it.getId());
+            expect(eventIds).toContain(THREAD_ROOT.event_id);
+            expect(eventIds).toContain(THREAD_REPLY.event_id);
         });
 
         it("should return relevant timeline from non-thread timelineSet when asking for the thread root", async () => {
@@ -1504,7 +1514,22 @@ describe("MatrixClient event timelines", function() {
                     state: [],
                     end: "end_token",
                 });
-            httpBackend.when("GET", "/rooms/!foo%3Abar/relations/" +
+            httpBackend.when("GET", "/rooms/!foo%3Abar/event/" +
+                encodeURIComponent(THREAD_ROOT.event_id!))
+                .respond(200, function() {
+                    return THREAD_ROOT;
+                });
+            httpBackend.when("GET", "/rooms/!foo%3Abar/event/" +
+                encodeURIComponent(THREAD_ROOT.event_id!))
+                .respond(200, function() {
+                    return THREAD_ROOT;
+                });
+            httpBackend.when("GET", "/rooms/!foo%3Abar/event/" +
+                encodeURIComponent(THREAD_ROOT.event_id!))
+                .respond(200, function() {
+                    return THREAD_ROOT;
+                });
+            httpBackend.when("GET", "/_matrix/client/v1/rooms/!foo%3Abar/relations/" +
                 encodeURIComponent(THREAD_ROOT.event_id!) + "/" +
                 encodeURIComponent(THREAD_RELATION_TYPE.name) + buildParams(Direction.Backward, "start_token"))
                 .respond(200, function() {
@@ -1513,7 +1538,7 @@ describe("MatrixClient event timelines", function() {
                         chunk: [],
                     };
                 });
-            httpBackend.when("GET", "/rooms/!foo%3Abar/relations/" +
+            httpBackend.when("GET", "/_matrix/client/v1/rooms/!foo%3Abar/relations/" +
                 encodeURIComponent(THREAD_ROOT.event_id!) + "/" +
                 encodeURIComponent(THREAD_RELATION_TYPE.name) + buildParams(Direction.Forward, "end_token"))
                 .respond(200, function() {
diff --git a/spec/integ/matrix-client-relations.spec.ts b/spec/integ/matrix-client-relations.spec.ts
index 456db2efb..5a4fa2bd0 100644
--- a/spec/integ/matrix-client-relations.spec.ts
+++ b/spec/integ/matrix-client-relations.spec.ts
@@ -55,7 +55,10 @@ describe("MatrixClient relations", () => {
         const response = client!.relations(roomId, '$event-0', null, null);
 
         httpBackend!
-            .when("GET", "/rooms/!room%3Ahere/relations/%24event-0?dir=b")
+            .when("GET", "/rooms/!room%3Ahere/event/%24event-0")
+            .respond(200, null);
+        httpBackend!
+            .when("GET", "/_matrix/client/v1/rooms/!room%3Ahere/relations/%24event-0?dir=b")
             .respond(200, { chunk: [], next_batch: 'NEXT' });
 
         await httpBackend!.flushAllExpected();
@@ -67,7 +70,10 @@ describe("MatrixClient relations", () => {
         const response = client!.relations(roomId, '$event-0', 'm.reference', null);
 
         httpBackend!
-            .when("GET", "/rooms/!room%3Ahere/relations/%24event-0/m.reference?dir=b")
+            .when("GET", "/rooms/!room%3Ahere/event/%24event-0")
+            .respond(200, null);
+        httpBackend!
+            .when("GET", "/_matrix/client/v1/rooms/!room%3Ahere/relations/%24event-0/m.reference?dir=b")
             .respond(200, { chunk: [], next_batch: 'NEXT' });
 
         await httpBackend!.flushAllExpected();
@@ -78,10 +84,13 @@ describe("MatrixClient relations", () => {
     it("should read related events with relation type and event type", async () => {
         const response = client!.relations(roomId, '$event-0', 'm.reference', 'm.room.message');
 
+        httpBackend!
+            .when("GET", "/rooms/!room%3Ahere/event/%24event-0")
+            .respond(200, null);
         httpBackend!
             .when(
                 "GET",
-                "/rooms/!room%3Ahere/relations/%24event-0/m.reference/m.room.message?dir=b",
+                "/_matrix/client/v1/rooms/!room%3Ahere/relations/%24event-0/m.reference/m.room.message?dir=b",
             )
             .respond(200, { chunk: [], next_batch: 'NEXT' });
 
@@ -98,10 +107,13 @@ describe("MatrixClient relations", () => {
             to: 'TO',
         });
 
+        httpBackend!
+            .when("GET", "/rooms/!room%3Ahere/event/%24event-0")
+            .respond(200, null);
         httpBackend!
             .when(
                 "GET",
-                "/rooms/!room%3Ahere/relations/%24event-0?dir=f&from=FROM&limit=10&to=TO",
+                "/_matrix/client/v1/rooms/!room%3Ahere/relations/%24event-0?dir=f&from=FROM&limit=10&to=TO",
             )
             .respond(200, { chunk: [], next_batch: 'NEXT' });
 
diff --git a/src/@types/requests.ts b/src/@types/requests.ts
index f9095455e..936ace5b4 100644
--- a/src/@types/requests.ts
+++ b/src/@types/requests.ts
@@ -153,7 +153,6 @@ export interface IRelationsRequestOpts {
 }
 
 export interface IRelationsResponse {
-    original_event: IEvent;
     chunk: IEvent[];
     next_batch?: string;
     prev_batch?: string;
diff --git a/src/client.ts b/src/client.ts
index 42709446e..355a0af0e 100644
--- a/src/client.ts
+++ b/src/client.ts
@@ -5469,7 +5469,8 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
 
                 timelineSet.addEventsToTimeline(events, true, timeline, resNewer.next_batch);
                 if (!resOlder.next_batch) {
-                    timelineSet.addEventsToTimeline([mapper(resOlder.original_event)], true, timeline, null);
+                    const originalEvent = await this.fetchRoomEvent(timelineSet.room.roomId, thread.id);
+                    timelineSet.addEventsToTimeline([mapper(originalEvent)], true, timeline, null);
                 }
                 timeline.setPaginationToken(resOlder.next_batch ?? null, Direction.Backward);
                 timeline.setPaginationToken(resNewer.next_batch ?? null, Direction.Forward);
@@ -5526,7 +5527,8 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
 
                 timelineSet.addEventsToTimeline(events, true, timeline, null);
                 if (!resOlder.next_batch) {
-                    timelineSet.addEventsToTimeline([mapper(resOlder.original_event)], true, timeline, null);
+                    const originalEvent = await this.fetchRoomEvent(timelineSet.room.roomId, thread.id);
+                    timelineSet.addEventsToTimeline([mapper(originalEvent)], true, timeline, null);
                 }
                 timeline.setPaginationToken(resOlder.next_batch ?? null, Direction.Backward);
                 timeline.setPaginationToken(null, Direction.Forward);
@@ -5878,7 +5880,8 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
                 const timelineSet = eventTimeline.getTimelineSet();
                 timelineSet.addEventsToTimeline(matrixEvents, backwards, eventTimeline, newToken ?? null);
                 if (!newToken && backwards) {
-                    timelineSet.addEventsToTimeline([mapper(res.original_event)], true, eventTimeline, null);
+                    const originalEvent = await this.fetchRoomEvent(eventTimeline.getRoomId() ?? "", thread.id);
+                    timelineSet.addEventsToTimeline([mapper(originalEvent)], true, eventTimeline, null);
                 }
                 this.processBeaconEvents(timelineSet.room, matrixEvents);
 
@@ -7099,15 +7102,13 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
         prevBatch?: string | null;
     }> {
         const fetchedEventType = eventType ? this.getEncryptedIfNeededEventType(roomId, eventType) : null;
-        const result = await this.fetchRelations(
-            roomId,
-            eventId,
-            relationType,
-            fetchedEventType,
-            opts);
+        const [eventResult, result] = await Promise.all([
+            this.fetchRoomEvent(roomId, eventId),
+            this.fetchRelations(roomId, eventId, relationType, fetchedEventType, opts),
+        ]);
         const mapper = this.getEventMapper();
 
-        const originalEvent = result.original_event ? mapper(result.original_event) : undefined;
+        const originalEvent = eventResult ? mapper(eventResult) : undefined;
         let events = result.chunk.map(mapper);
 
         if (fetchedEventType === EventType.RoomMessageEncrypted) {
@@ -7669,7 +7670,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
             });
         return this.http.authedRequest(
             Method.Get, path, undefined, undefined, {
-                prefix: ClientPrefix.Unstable,
+                prefix: ClientPrefix.V1,
             },
         );
     }