diff --git a/syncapi/streams/stream_accountdata.go b/syncapi/streams/stream_accountdata.go
index f3e7fbdaa..ecbbb6f5f 100644
--- a/syncapi/streams/stream_accountdata.go
+++ b/syncapi/streams/stream_accountdata.go
@@ -91,9 +91,9 @@ func (p *AccountDataStreamProvider) IncrementalSync(
 				}
 			} else {
 				if roomData, ok := dataRes.RoomAccountData[roomID][dataType]; ok {
-					joinData := *types.NewJoinResponse()
-					if existing, ok := req.Response.Rooms.Join[roomID]; ok {
-						joinData = existing
+					joinData, ok := req.Response.Rooms.Join[roomID]
+					if !ok {
+						joinData = *types.NewJoinResponse()
 					}
 					joinData.AccountData.Events = append(
 						joinData.AccountData.Events,
diff --git a/syncapi/streams/stream_typing.go b/syncapi/streams/stream_typing.go
index a6f7c7a06..4fb6ecf99 100644
--- a/syncapi/streams/stream_typing.go
+++ b/syncapi/streams/stream_typing.go
@@ -4,10 +4,11 @@ import (
 	"context"
 	"encoding/json"
 
+	"github.com/matrix-org/gomatrixserverlib"
+
 	"github.com/matrix-org/dendrite/internal/caching"
 	"github.com/matrix-org/dendrite/syncapi/storage"
 	"github.com/matrix-org/dendrite/syncapi/types"
-	"github.com/matrix-org/gomatrixserverlib"
 )
 
 type TypingStreamProvider struct {
@@ -35,9 +36,9 @@ func (p *TypingStreamProvider) IncrementalSync(
 			continue
 		}
 
-		jr := *types.NewJoinResponse()
-		if existing, ok := req.Response.Rooms.Join[roomID]; ok {
-			jr = existing
+		jr, ok := req.Response.Rooms.Join[roomID]
+		if !ok {
+			jr = *types.NewJoinResponse()
 		}
 
 		if users, updated := p.EDUCache.GetTypingUsersIfUpdatedAfter(