diff --git a/internal/eventutil/events.go b/internal/eventutil/events.go
index e4640175..958999ee 100644
--- a/internal/eventutil/events.go
+++ b/internal/eventutil/events.go
@@ -72,7 +72,7 @@ func BuildEvent(
 		return nil, err
 	}
 	proto.Version = verImpl
-	if err := addPrevEventsToEvent(proto, eventsNeeded, queryRes); err != nil {
+	if err = addPrevEventsToEvent(proto, eventsNeeded, queryRes); err != nil {
 		return nil, err
 	}
 
diff --git a/roomserver/api/wrapper.go b/roomserver/api/wrapper.go
index 8b27ebac..14115639 100644
--- a/roomserver/api/wrapper.go
+++ b/roomserver/api/wrapper.go
@@ -246,9 +246,7 @@ func GenerateCreateContent(ctx context.Context, roomVer gomatrixserverlib.RoomVe
 		var finalAdditionalCreators []string
 		creatorsSet := make(map[string]struct{})
 		var unverifiedCreators []string
-		for _, add := range additionalCreators {
-			unverifiedCreators = append(unverifiedCreators, add)
-		}
+		unverifiedCreators = append(unverifiedCreators, additionalCreators...)
 		// they get added to any additional creators specified already
 		existingAdditionalCreators, ok := createContent["additional_creators"].([]any)
 		if ok {
diff --git a/roomserver/internal/perform/perform_create_room.go b/roomserver/internal/perform/perform_create_room.go
index aac81253..aabd92f1 100644
--- a/roomserver/internal/perform/perform_create_room.go
+++ b/roomserver/internal/perform/perform_create_room.go
@@ -90,7 +90,7 @@ func (c *Creator) PerformCreateRoom(ctx context.Context, userID spec.UserID, roo
 		createEvent gomatrixserverlib.PDU
 		jsonErr     *util.JSONResponse
 	)
-	authEvents, err := gomatrixserverlib.NewAuthEvents(nil)
+	authEvents, _ := gomatrixserverlib.NewAuthEvents(nil)
 	if createRequest.CreateEvent != nil {
 		createEvent, err = verImpl.NewEventFromTrustedJSON(createRequest.CreateEvent, false)
 		if err != nil {
@@ -100,15 +100,21 @@ func (c *Creator) PerformCreateRoom(ctx context.Context, userID spec.UserID, roo
 				JSON: spec.InternalServerError{},
 			}
 		}
-		authEvents.AddEvent(createEvent)
+		if err = authEvents.AddEvent(createEvent); err != nil {
+			util.GetLogger(ctx).WithError(err).Error("gomatrixserverlib.AuthEvents.AddEvent failed")
+			return "", &util.JSONResponse{
+				Code: http.StatusInternalServerError,
+				JSON: spec.InternalServerError{},
+			}
+		}
 	} else {
 		var additionalCreators []string
 		if createRequest.StatePreset == spec.PresetTrustedPrivateChat {
 			additionalCreators = createRequest.InvitedUsers
 		}
-		createContent, err := api.GenerateCreateContent(ctx, createRequest.RoomVersion, string(senderID), createRequest.CreationContent, additionalCreators)
-		if err != nil {
-			util.GetLogger(ctx).WithError(err).Error("GenerateCreateContent failed")
+		createContent, contentErr := api.GenerateCreateContent(ctx, createRequest.RoomVersion, string(senderID), createRequest.CreationContent, additionalCreators)
+		if contentErr != nil {
+			util.GetLogger(ctx).WithError(contentErr).Error("GenerateCreateContent failed")
 			return "", &util.JSONResponse{
 				Code: http.StatusBadRequest,
 				JSON: spec.BadJSON("invalid create content"),
diff --git a/roomserver/internal/perform/perform_upgrade.go b/roomserver/internal/perform/perform_upgrade.go
index 552e5437..dd26dd3a 100644
--- a/roomserver/internal/perform/perform_upgrade.go
+++ b/roomserver/internal/perform/perform_upgrade.go
@@ -70,7 +70,7 @@ func (r *Upgrader) performRoomUpgrade(
 		RoomID: roomID,
 	}
 	oldRoomRes := &api.QueryLatestEventsAndStateResponse{}
-	if err := r.URSAPI.QueryLatestEventsAndState(ctx, oldRoomReq, oldRoomRes); err != nil {
+	if err = r.URSAPI.QueryLatestEventsAndState(ctx, oldRoomReq, oldRoomRes); err != nil {
 		return "", fmt.Errorf("Failed to get latest state: %s", err)
 	}
 	var oldCreateEvent *types.HeaderedEvent
@@ -98,7 +98,7 @@ func (r *Upgrader) performRoomUpgrade(
 		} `json:"predecessor"`
 	}{}
 	// keep existing values in old room e.g type/m.federate
-	if err := json.Unmarshal(oldCreateEvent.Content(), &content); err != nil {
+	if err = json.Unmarshal(oldCreateEvent.Content(), &content); err != nil {
 		return "", fmt.Errorf("failed to copy old create event content to new create event: %s", err)
 	}
 	content.Predecessor.RoomID = roomID
@@ -373,8 +373,8 @@ func (r *Upgrader) userIsAuthorized(ctx context.Context, senderID spec.SenderID,
 // Return the events to create AFTER the new create event
 // nolint:gocyclo
 func (r *Upgrader) generateInitialEvents(
-	ctx context.Context, oldRoom *api.QueryLatestEventsAndStateResponse, senderID spec.SenderID, roomID string, newVersion gomatrixserverlib.RoomVersion,
-	tombstoneEvent *types.HeaderedEvent, creators []string) ([]gomatrixserverlib.FledglingEvent, error) {
+	ctx context.Context, oldRoom *api.QueryLatestEventsAndStateResponse, senderID spec.SenderID, _ string, newVersion gomatrixserverlib.RoomVersion,
+	_ *types.HeaderedEvent, creators []string) ([]gomatrixserverlib.FledglingEvent, error) {
 
 	state := make(map[gomatrixserverlib.StateKeyTuple]*types.HeaderedEvent, len(oldRoom.StateEvents))
 	for _, event := range oldRoom.StateEvents {