diff --git a/clientapi/producers/roomserver.go b/clientapi/producers/roomserver.go
index e50561a70..0fe2d556b 100644
--- a/clientapi/producers/roomserver.go
+++ b/clientapi/producers/roomserver.go
@@ -40,9 +40,11 @@ func (c *RoomserverProducer) SendEvents(
 ) (string, error) {
 	ires := make([]api.InputRoomEvent, len(events))
 	for i, event := range events {
+		roomVersion := gomatrixserverlib.RoomVersionV1
+
 		ires[i] = api.InputRoomEvent{
 			Kind:          api.KindNew,
-			Event:         event,
+			Event:         event.Headered(roomVersion),
 			AuthEventIDs:  event.AuthEventIDs(),
 			SendAsServer:  string(sendAsServer),
 			TransactionID: txnID,
@@ -61,11 +63,14 @@ func (c *RoomserverProducer) SendEventWithState(
 		return err
 	}
 
+	// TODO: Room version here
+	roomVersion := gomatrixserverlib.RoomVersionV1
+
 	ires := make([]api.InputRoomEvent, len(outliers)+1)
 	for i, outlier := range outliers {
 		ires[i] = api.InputRoomEvent{
 			Kind:         api.KindOutlier,
-			Event:        outlier,
+			Event:        outlier.Headered(roomVersion),
 			AuthEventIDs: outlier.AuthEventIDs(),
 		}
 	}
@@ -77,7 +82,7 @@ func (c *RoomserverProducer) SendEventWithState(
 
 	ires[len(outliers)] = api.InputRoomEvent{
 		Kind:          api.KindNew,
-		Event:         event,
+		Event:         event.Headered(roomVersion),
 		AuthEventIDs:  event.AuthEventIDs(),
 		HasState:      true,
 		StateEventIDs: stateEventIDs,
@@ -104,8 +109,13 @@ func (c *RoomserverProducer) SendInputRoomEvents(
 func (c *RoomserverProducer) SendInvite(
 	ctx context.Context, inviteEvent gomatrixserverlib.Event,
 ) error {
+	// TODO: Room version here
+	roomVersion := gomatrixserverlib.RoomVersionV1
+
 	request := api.InputRoomEventsRequest{
-		InputInviteEvents: []api.InputInviteEvent{{Event: inviteEvent}},
+		InputInviteEvents: []api.InputInviteEvent{{
+			Event: inviteEvent.Headered(roomVersion),
+		}},
 	}
 	var response api.InputRoomEventsResponse
 	return c.InputAPI.InputRoomEvents(ctx, &request, &response)
diff --git a/clientapi/routing/createroom.go b/clientapi/routing/createroom.go
index c9623acb9..3465d9854 100644
--- a/clientapi/routing/createroom.go
+++ b/clientapi/routing/createroom.go
@@ -180,7 +180,8 @@ func createRoom(
 	}
 
 	r.CreationContent["creator"] = userID
-	r.CreationContent["room_version"] = "1" // TODO: We set this to 1 before we support Room versioning
+	// TODO: Room version here
+	r.CreationContent["room_version"] = gomatrixserverlib.RoomVersionV1
 
 	// TODO: visibility/presets/raw initial state
 	// TODO: Create room alias association
diff --git a/cmd/create-room-events/main.go b/cmd/create-room-events/main.go
index 8475914f0..ef442a0c4 100644
--- a/cmd/create-room-events/main.go
+++ b/cmd/create-room-events/main.go
@@ -125,7 +125,7 @@ func writeEvent(event gomatrixserverlib.Event) {
 	if *format == "InputRoomEvent" {
 		var ire api.InputRoomEvent
 		ire.Kind = api.KindNew
-		ire.Event = event
+		ire.Event = event.Headered(gomatrixserverlib.RoomVersionV1)
 		authEventIDs := []string{}
 		for _, ref := range b.AuthEvents {
 			authEventIDs = append(authEventIDs, ref.EventID)
diff --git a/roomserver/alias/alias.go b/roomserver/alias/alias.go
index 59da35b3f..f4f5c20ce 100644
--- a/roomserver/alias/alias.go
+++ b/roomserver/alias/alias.go
@@ -250,10 +250,13 @@ func (r *RoomserverAliasAPI) sendUpdatedAliasesEvent(
 		return err
 	}
 
+	// TODO: Room version here
+	roomVersion := gomatrixserverlib.RoomVersionV1
+
 	// Create the request
 	ire := roomserverAPI.InputRoomEvent{
 		Kind:         roomserverAPI.KindNew,
-		Event:        event,
+		Event:        event.Headered(roomVersion),
 		AuthEventIDs: event.AuthEventIDs(),
 		SendAsServer: serverName,
 	}
diff --git a/roomserver/api/input.go b/roomserver/api/input.go
index 9643a927c..f07cc0221 100644
--- a/roomserver/api/input.go
+++ b/roomserver/api/input.go
@@ -51,7 +51,7 @@ type InputRoomEvent struct {
 	// This controls how the event is processed.
 	Kind int `json:"kind"`
 	// The event JSON for the event to add.
-	Event gomatrixserverlib.Event `json:"event"`
+	Event gomatrixserverlib.HeaderedEvent `json:"event"`
 	// List of state event IDs that authenticate this event.
 	// These are likely derived from the "auth_events" JSON key of the event.
 	// But can be different because the "auth_events" key can be incomplete or wrong.
@@ -85,7 +85,7 @@ type TransactionID struct {
 // the usual context a matrix room event would have. We usually do not have
 // access to the events needed to check the event auth rules for the invite.
 type InputInviteEvent struct {
-	Event gomatrixserverlib.Event `json:"event"`
+	Event gomatrixserverlib.HeaderedEvent `json:"event"`
 }
 
 // InputRoomEventsRequest is a request to InputRoomEvents
diff --git a/roomserver/input/events.go b/roomserver/input/events.go
index a3b70753e..7fbc5d8a9 100644
--- a/roomserver/input/events.go
+++ b/roomserver/input/events.go
@@ -95,7 +95,7 @@ func processRoomEvent(
 	event := input.Event
 
 	// Check that the event passes authentication checks and work out the numeric IDs for the auth events.
-	authEventNIDs, err := checkAuthEvents(ctx, db, event, input.AuthEventIDs)
+	authEventNIDs, err := checkAuthEvents(ctx, db, event.Event, input.AuthEventIDs)
 	if err != nil {
 		return
 	}
@@ -112,7 +112,7 @@ func processRoomEvent(
 	}
 
 	// Store the event
-	roomNID, stateAtEvent, err := db.StoreEvent(ctx, event, input.TransactionID, authEventNIDs)
+	roomNID, stateAtEvent, err := db.StoreEvent(ctx, event.Event, input.TransactionID, authEventNIDs)
 	if err != nil {
 		return
 	}
@@ -127,7 +127,7 @@ func processRoomEvent(
 	if stateAtEvent.BeforeStateSnapshotNID == 0 {
 		// We haven't calculated a state for this event yet.
 		// Lets calculate one.
-		err = calculateAndSetState(ctx, db, input, roomNID, &stateAtEvent, event)
+		err = calculateAndSetState(ctx, db, input, roomNID, &stateAtEvent, event.Event)
 		if err != nil {
 			return
 		}
@@ -140,7 +140,7 @@ func processRoomEvent(
 
 	// Update the extremities of the event graph for the room
 	return event.EventID(), updateLatestEvents(
-		ctx, db, ow, roomNID, stateAtEvent, event, input.SendAsServer, input.TransactionID,
+		ctx, db, ow, roomNID, stateAtEvent, event.Event, input.SendAsServer, input.TransactionID,
 	)
 }
 
@@ -234,7 +234,7 @@ func processInviteEvent(
 		return nil
 	}
 
-	outputUpdates, err := updateToInviteMembership(updater, &input.Event, nil)
+	outputUpdates, err := updateToInviteMembership(updater, &input.Event.Event, nil)
 	if err != nil {
 		return err
 	}