diff --git a/federationapi/routing/backfill.go b/federationapi/routing/backfill.go
index 31005209..462b8ccf 100644
--- a/federationapi/routing/backfill.go
+++ b/federationapi/routing/backfill.go
@@ -15,12 +15,12 @@
 package routing
 
 import (
-	"encoding/json"
 	"fmt"
 	"net/http"
 	"strconv"
 	"time"
 
+	jsoniter "github.com/json-iterator/go"
 	"github.com/matrix-org/dendrite/clientapi/jsonerror"
 	"github.com/matrix-org/dendrite/roomserver/api"
 	"github.com/matrix-org/dendrite/setup/config"
@@ -102,7 +102,7 @@ func Backfill(
 		}
 	}
 
-	eventJSONs := []json.RawMessage{}
+	eventJSONs := []jsoniter.RawMessage{}
 	for _, e := range gomatrixserverlib.ReverseTopologicalOrdering(
 		evs,
 		gomatrixserverlib.TopologicalOrderByPrevEvents,
diff --git a/federationapi/routing/events.go b/federationapi/routing/events.go
index 312ef9f8..c40bc216 100644
--- a/federationapi/routing/events.go
+++ b/federationapi/routing/events.go
@@ -16,10 +16,10 @@ package routing
 
 import (
 	"context"
-	"encoding/json"
 	"net/http"
 	"time"
 
+	jsoniter "github.com/json-iterator/go"
 	"github.com/matrix-org/dendrite/roomserver/api"
 	"github.com/matrix-org/gomatrixserverlib"
 	"github.com/matrix-org/util"
@@ -45,7 +45,7 @@ func GetEvent(
 	return util.JSONResponse{Code: http.StatusOK, JSON: gomatrixserverlib.Transaction{
 		Origin:         origin,
 		OriginServerTS: gomatrixserverlib.AsTimestamp(time.Now()),
-		PDUs: []json.RawMessage{
+		PDUs: []jsoniter.RawMessage{
 			event.JSON(),
 		},
 	}}
diff --git a/federationapi/routing/send.go b/federationapi/routing/send.go
index 96b5355e..c4f2a650 100644
--- a/federationapi/routing/send.go
+++ b/federationapi/routing/send.go
@@ -23,6 +23,7 @@ import (
 	"sync"
 	"time"
 
+	jsoniter "github.com/json-iterator/go"
 	"github.com/matrix-org/dendrite/clientapi/jsonerror"
 	eduserverAPI "github.com/matrix-org/dendrite/eduserver/api"
 	keyapi "github.com/matrix-org/dendrite/keyserver/api"
@@ -56,7 +57,7 @@ func Send(
 	}
 
 	var txnEvents struct {
-		PDUs []json.RawMessage       `json:"pdus"`
+		PDUs []jsoniter.RawMessage   `json:"pdus"`
 		EDUs []gomatrixserverlib.EDU `json:"edus"`
 	}
 
diff --git a/federationapi/routing/send_test.go b/federationapi/routing/send_test.go
index 8bdf54c4..020ccd96 100644
--- a/federationapi/routing/send_test.go
+++ b/federationapi/routing/send_test.go
@@ -2,12 +2,12 @@ package routing
 
 import (
 	"context"
-	"encoding/json"
 	"fmt"
 	"reflect"
 	"testing"
 	"time"
 
+	jsoniter "github.com/json-iterator/go"
 	eduAPI "github.com/matrix-org/dendrite/eduserver/api"
 	"github.com/matrix-org/dendrite/internal/test"
 	"github.com/matrix-org/dendrite/roomserver/api"
@@ -21,7 +21,7 @@ const (
 
 var (
 	testRoomVersion = gomatrixserverlib.RoomVersionV1
-	testData        = []json.RawMessage{
+	testData        = []jsoniter.RawMessage{
 		[]byte(`{"auth_events":[],"content":{"creator":"@userid:kaer.morhen"},"depth":0,"event_id":"$0ok8ynDp7kjc95e3:kaer.morhen","hashes":{"sha256":"17kPoH+h0Dk4Omn7Sus0qMb6+oGcf+CZFEgDhv7UKWs"},"origin":"kaer.morhen","origin_server_ts":0,"prev_events":[],"prev_state":[],"room_id":"!roomid:kaer.morhen","sender":"@userid:kaer.morhen","signatures":{"kaer.morhen":{"ed25519:auto":"jP4a04f5/F10Pw95FPpdCyKAO44JOwUQ/MZOOeA/RTU1Dn+AHPMzGSaZnuGjRr/xQuADt+I3ctb5ZQfLKNzHDw"}},"state_key":"","type":"m.room.create"}`),
 		[]byte(`{"auth_events":[["$0ok8ynDp7kjc95e3:kaer.morhen",{"sha256":"sWCi6Ckp9rDimQON+MrUlNRkyfZ2tjbPbWfg2NMB18Q"}]],"content":{"membership":"join"},"depth":1,"event_id":"$LEwEu0kxrtu5fOiS:kaer.morhen","hashes":{"sha256":"B7M88PhXf3vd1LaFtjQutFu4x/w7fHD28XKZ4sAsJTo"},"origin":"kaer.morhen","origin_server_ts":0,"prev_events":[["$0ok8ynDp7kjc95e3:kaer.morhen",{"sha256":"sWCi6Ckp9rDimQON+MrUlNRkyfZ2tjbPbWfg2NMB18Q"}]],"prev_state":[],"room_id":"!roomid:kaer.morhen","sender":"@userid:kaer.morhen","signatures":{"kaer.morhen":{"ed25519:auto":"p2vqmuJn7ZBRImctSaKbXCAxCcBlIjPH9JHte1ouIUGy84gpu4eLipOvSBCLL26hXfC0Zrm4WUto6Hr+ohdrCg"}},"state_key":"@userid:kaer.morhen","type":"m.room.member"}`),
 		[]byte(`{"auth_events":[["$0ok8ynDp7kjc95e3:kaer.morhen",{"sha256":"sWCi6Ckp9rDimQON+MrUlNRkyfZ2tjbPbWfg2NMB18Q"}],["$LEwEu0kxrtu5fOiS:kaer.morhen",{"sha256":"1aKajq6DWHru1R1HJjvdWMEavkJJHGaTmPvfuERUXaA"}]],"content":{"join_rule":"public"},"depth":2,"event_id":"$SMHlqUrNhhBBRLeN:kaer.morhen","hashes":{"sha256":"vIuJQvmMjrGxshAkj1SXe0C4RqvMbv4ZADDw9pFCWqQ"},"origin":"kaer.morhen","origin_server_ts":0,"prev_events":[["$LEwEu0kxrtu5fOiS:kaer.morhen",{"sha256":"1aKajq6DWHru1R1HJjvdWMEavkJJHGaTmPvfuERUXaA"}]],"prev_state":[],"room_id":"!roomid:kaer.morhen","sender":"@userid:kaer.morhen","signatures":{"kaer.morhen":{"ed25519:auto":"hBMsb3Qppo3RaqqAl4JyTgaiWEbW5hlckATky6PrHun+F3YM203TzG7w9clwuQU5F5pZoB1a6nw+to0hN90FAw"}},"state_key":"","type":"m.room.join_rules"}`),
@@ -362,7 +362,7 @@ func (c *txnFedClient) LookupMissingEvents(ctx context.Context, s gomatrixserver
 	return c.getMissingEvents(missing)
 }
 
-func mustCreateTransaction(rsAPI api.RoomserverInternalAPI, fedClient txnFederationClient, pdus []json.RawMessage) *txnReq {
+func mustCreateTransaction(rsAPI api.RoomserverInternalAPI, fedClient txnFederationClient, pdus []jsoniter.RawMessage) *txnReq {
 	t := &txnReq{
 		rsAPI:      rsAPI,
 		eduAPI:     &testEDUProducer{},
@@ -445,7 +445,7 @@ func TestBasicTransaction(t *testing.T) {
 			}
 		},
 	}
-	pdus := []json.RawMessage{
+	pdus := []jsoniter.RawMessage{
 		testData[len(testData)-1], // a message event
 	}
 	txn := mustCreateTransaction(rsAPI, &txnFedClient{}, pdus)
@@ -465,7 +465,7 @@ func TestTransactionFailAuthChecks(t *testing.T) {
 			}
 		},
 	}
-	pdus := []json.RawMessage{
+	pdus := []jsoniter.RawMessage{
 		testData[len(testData)-1], // a message event
 	}
 	txn := mustCreateTransaction(rsAPI, &txnFedClient{}, pdus)
@@ -550,7 +550,7 @@ func TestTransactionFetchMissingPrevEvents(t *testing.T) {
 		},
 	}
 
-	pdus := []json.RawMessage{
+	pdus := []jsoniter.RawMessage{
 		inputEvent.JSON(),
 	}
 	txn := mustCreateTransaction(rsAPI, cli, pdus)
@@ -713,7 +713,7 @@ func TestTransactionFetchMissingStateByStateIDs(t *testing.T) {
 		// /event for event B returns it
 		getEvent: map[string]gomatrixserverlib.Transaction{
 			eventB.EventID(): {
-				PDUs: []json.RawMessage{
+				PDUs: []jsoniter.RawMessage{
 					eventB.JSON(),
 				},
 			},
@@ -735,7 +735,7 @@ func TestTransactionFetchMissingStateByStateIDs(t *testing.T) {
 		},
 	}
 
-	pdus := []json.RawMessage{
+	pdus := []jsoniter.RawMessage{
 		eventD.JSON(),
 	}
 	txn := mustCreateTransaction(rsAPI, cli, pdus)
diff --git a/federationsender/consumers/eduserver.go b/federationsender/consumers/eduserver.go
index 6d11eb88..a9b6e9bf 100644
--- a/federationsender/consumers/eduserver.go
+++ b/federationsender/consumers/eduserver.go
@@ -20,6 +20,7 @@ import (
 	"fmt"
 
 	"github.com/Shopify/sarama"
+	jsoniter "github.com/json-iterator/go"
 	"github.com/matrix-org/dendrite/eduserver/api"
 	"github.com/matrix-org/dendrite/federationsender/queue"
 	"github.com/matrix-org/dendrite/federationsender/storage"
@@ -131,7 +132,7 @@ func (t *OutputEDUConsumer) onSendToDeviceEvent(msg *sarama.ConsumerMessage) err
 		Sender:    ote.Sender,
 		Type:      ote.Type,
 		MessageID: util.RandomString(32),
-		Messages: map[string]map[string]json.RawMessage{
+		Messages: map[string]map[string]jsoniter.RawMessage{
 			ote.UserID: {
 				ote.DeviceID: ote.Content,
 			},
diff --git a/federationsender/queue/destinationqueue.go b/federationsender/queue/destinationqueue.go
index c8b0bf65..19272794 100644
--- a/federationsender/queue/destinationqueue.go
+++ b/federationsender/queue/destinationqueue.go
@@ -16,11 +16,11 @@ package queue
 
 import (
 	"context"
-	"encoding/json"
 	"fmt"
 	"sync"
 	"time"
 
+	jsoniter "github.com/json-iterator/go"
 	"github.com/matrix-org/dendrite/federationsender/statistics"
 	"github.com/matrix-org/dendrite/federationsender/storage"
 	"github.com/matrix-org/dendrite/federationsender/storage/shared"
@@ -367,7 +367,7 @@ func (oq *destinationQueue) nextTransaction(
 
 	// Create the transaction.
 	t := gomatrixserverlib.Transaction{
-		PDUs: []json.RawMessage{},
+		PDUs: []jsoniter.RawMessage{},
 		EDUs: []gomatrixserverlib.EDU{},
 	}
 	t.Origin = oq.origin
@@ -390,7 +390,7 @@ func (oq *destinationQueue) nextTransaction(
 		if pdu == nil || pdu.pdu == nil {
 			continue
 		}
-		// Append the JSON of the event, since this is a json.RawMessage type in the
+		// Append the JSON of the event, since this is a jsoniter.RawMessage type in the
 		// gomatrixserverlib.Transaction struct
 		t.PDUs = append(t.PDUs, pdu.pdu.JSON())
 		pduReceipts = append(pduReceipts, pdu.receipt)
diff --git a/go.mod b/go.mod
index 891d0f57..6e8dffc3 100644
--- a/go.mod
+++ b/go.mod
@@ -7,6 +7,7 @@ require (
 	github.com/gologme/log v1.2.0
 	github.com/gorilla/mux v1.8.0
 	github.com/hashicorp/golang-lru v0.5.4
+	github.com/json-iterator/go v1.1.10
 	github.com/lib/pq v1.8.0
 	github.com/libp2p/go-libp2p v0.11.0
 	github.com/libp2p/go-libp2p-circuit v0.3.1
@@ -22,7 +23,7 @@ require (
 	github.com/matrix-org/go-http-js-libp2p v0.0.0-20200518170932-783164aeeda4
 	github.com/matrix-org/go-sqlite3-js v0.0.0-20200522092705-bc8506ccbcf3
 	github.com/matrix-org/gomatrix v0.0.0-20200827122206-7dd5e2a05bcd
-	github.com/matrix-org/gomatrixserverlib v0.0.0-20210122154608-a38974bd8a37
+	github.com/matrix-org/gomatrixserverlib v0.0.0-20210125150012-01e52c47a2a5
 	github.com/matrix-org/naffka v0.0.0-20200901083833-bcdd62999a91
 	github.com/matrix-org/util v0.0.0-20200807132607-55161520e1d4
 	github.com/mattn/go-sqlite3 v1.14.2
diff --git a/go.sum b/go.sum
index acdfaf2c..644b13b0 100644
--- a/go.sum
+++ b/go.sum
@@ -282,6 +282,7 @@ github.com/jessevdk/go-flags v0.0.0-20141203071132-1679536dcc89/go.mod h1:4FA24M
 github.com/jessevdk/go-flags v1.4.0/go.mod h1:4FA24M0QyGHXBuZZK/XkWh8h0e1EYbRYJSGM75WSRxI=
 github.com/jrick/logrotate v1.0.0/go.mod h1:LNinyqDIJnpAur+b8yyulnQw/wDuN1+BYKlTRt3OuAQ=
 github.com/json-iterator/go v1.1.6/go.mod h1:+SdeFBvtyEkXs7REEP0seUULqWtbJapLOCVDaaPEHmU=
+github.com/json-iterator/go v1.1.10 h1:Kz6Cvnvv2wGdaG/V8yMvfkmNiXq9Ya2KUv4rouJJr68=
 github.com/json-iterator/go v1.1.10/go.mod h1:KdQUCv79m/52Kvf8AW2vK1V8akMuk1QjK/uOdHXbAo4=
 github.com/jstemmer/go-junit-report v0.0.0-20190106144839-af01ea7f8024/go.mod h1:6v2b51hI/fHJwM22ozAgKL4VKDeJcHhJFhtBdhmNjmU=
 github.com/julienschmidt/httprouter v1.2.0/go.mod h1:SYymIcj16QtmaHHD7aYtjjsJG7VTCxuUUipMqKk8s4w=
@@ -569,6 +570,8 @@ github.com/matrix-org/gomatrix v0.0.0-20200827122206-7dd5e2a05bcd h1:xVrqJK3xHRE
 github.com/matrix-org/gomatrix v0.0.0-20200827122206-7dd5e2a05bcd/go.mod h1:/gBX06Kw0exX1HrwmoBibFA98yBk/jxKpGVeyQbff+s=
 github.com/matrix-org/gomatrixserverlib v0.0.0-20210122154608-a38974bd8a37 h1:si2CZZpwOLWZfDXfgHPkaTlaAkdJvpJzr1zVqyKXd0I=
 github.com/matrix-org/gomatrixserverlib v0.0.0-20210122154608-a38974bd8a37/go.mod h1:JsAzE1Ll3+gDWS9JSUHPJiiyAksvOOnGWF2nXdg4ZzU=
+github.com/matrix-org/gomatrixserverlib v0.0.0-20210125150012-01e52c47a2a5 h1:CB4qoqmsNCozYHZi0051R5pg8F8QJWdwMyDfmdRfk7s=
+github.com/matrix-org/gomatrixserverlib v0.0.0-20210125150012-01e52c47a2a5/go.mod h1:JsAzE1Ll3+gDWS9JSUHPJiiyAksvOOnGWF2nXdg4ZzU=
 github.com/matrix-org/naffka v0.0.0-20200901083833-bcdd62999a91 h1:HJ6U3S3ljJqNffYMcIeAncp5qT/i+ZMiJ2JC2F0aXP4=
 github.com/matrix-org/naffka v0.0.0-20200901083833-bcdd62999a91/go.mod h1:sjyPyRxKM5uw1nD2cJ6O2OxI6GOqyVBfNXqKjBZTBZE=
 github.com/matrix-org/util v0.0.0-20190711121626-527ce5ddefc7 h1:ntrLa/8xVzeSs8vHFHK25k0C+NV74sYMJnNSg5NoSRo=
@@ -607,8 +610,10 @@ github.com/minio/sha256-simd v0.1.1/go.mod h1:B5e1o+1/KgNmWrSQK08Y6Z1Vb5pwIktudl
 github.com/mitchellh/go-homedir v1.1.0/go.mod h1:SfyaCUpYCn1Vlf4IUYiD9fPX4A5wJrkLzIz1N1q0pr0=
 github.com/mitchellh/mapstructure v1.1.2/go.mod h1:FVVH3fgwuzCH5S8UJGiWEs2h04kUh9fWfEaFds41c1Y=
 github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
+github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd h1:TRLaZ9cD/w8PVh93nsPXa1VrQ6jlwL5oN8l14QlcNfg=
 github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
 github.com/modern-go/reflect2 v0.0.0-20180701023420-4b7aa43c6742/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3RllmbCylyMrvgv0=
+github.com/modern-go/reflect2 v1.0.1 h1:9f412s+6RmYXLWZSEzVVgPGK7C2PphHj5RJrvfx9AWI=
 github.com/modern-go/reflect2 v1.0.1/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3RllmbCylyMrvgv0=
 github.com/mr-tron/base58 v1.1.0/go.mod h1:xcD2VGqlgYjBdcBLw+TuYLr8afG+Hj8g2eTVqeSzSU8=
 github.com/mr-tron/base58 v1.1.1/go.mod h1:xcD2VGqlgYjBdcBLw+TuYLr8afG+Hj8g2eTVqeSzSU8=