diff --git a/clientapi/routing/createroom.go b/clientapi/routing/createroom.go
index 9be0b512..2d886746 100644
--- a/clientapi/routing/createroom.go
+++ b/clientapi/routing/createroom.go
@@ -217,7 +217,8 @@ func createRoom(
 		roomAlias = fmt.Sprintf("#%s:%s", r.RoomAliasName, cfg.Matrix.ServerName)
 		// check it's free TODO: This races but is better than nothing
 		hasAliasReq := roomserverAPI.GetRoomIDForAliasRequest{
-			Alias: roomAlias,
+			Alias:              roomAlias,
+			IncludeAppservices: false,
 		}
 
 		var aliasResp roomserverAPI.GetRoomIDForAliasResponse
diff --git a/clientapi/routing/directory.go b/clientapi/routing/directory.go
index 1b844c4e..0e994b64 100644
--- a/clientapi/routing/directory.go
+++ b/clientapi/routing/directory.go
@@ -61,9 +61,12 @@ func DirectoryRoom(
 	var res roomDirectoryResponse
 
 	// Query the roomserver API to check if the alias exists locally.
-	queryReq := roomserverAPI.GetRoomIDForAliasRequest{Alias: roomAlias}
-	var queryRes roomserverAPI.GetRoomIDForAliasResponse
-	if err = rsAPI.GetRoomIDForAlias(req.Context(), &queryReq, &queryRes); err != nil {
+	queryReq := &roomserverAPI.GetRoomIDForAliasRequest{
+		Alias:              roomAlias,
+		IncludeAppservices: true,
+	}
+	queryRes := &roomserverAPI.GetRoomIDForAliasResponse{}
+	if err = rsAPI.GetRoomIDForAlias(req.Context(), queryReq, queryRes); err != nil {
 		util.GetLogger(req.Context()).WithError(err).Error("rsAPI.GetRoomIDForAlias failed")
 		return jsonerror.InternalServerError()
 	}
diff --git a/federationapi/routing/query.go b/federationapi/routing/query.go
index 6c25b4d3..b4158f0c 100644
--- a/federationapi/routing/query.go
+++ b/federationapi/routing/query.go
@@ -53,9 +53,12 @@ func RoomAliasToID(
 	var resp gomatrixserverlib.RespDirectory
 
 	if domain == cfg.Matrix.ServerName {
-		queryReq := roomserverAPI.GetRoomIDForAliasRequest{Alias: roomAlias}
-		var queryRes roomserverAPI.GetRoomIDForAliasResponse
-		if err = rsAPI.GetRoomIDForAlias(httpReq.Context(), &queryReq, &queryRes); err != nil {
+		queryReq := &roomserverAPI.GetRoomIDForAliasRequest{
+			Alias:              roomAlias,
+			IncludeAppservices: true,
+		}
+		queryRes := &roomserverAPI.GetRoomIDForAliasResponse{}
+		if err = rsAPI.GetRoomIDForAlias(httpReq.Context(), queryReq, queryRes); err != nil {
 			util.GetLogger(httpReq.Context()).WithError(err).Error("aliasAPI.GetRoomIDForAlias failed")
 			return jsonerror.InternalServerError()
 		}
diff --git a/roomserver/api/alias.go b/roomserver/api/alias.go
index 61fdc611..2eb91129 100644
--- a/roomserver/api/alias.go
+++ b/roomserver/api/alias.go
@@ -34,6 +34,9 @@ type SetRoomAliasResponse struct {
 type GetRoomIDForAliasRequest struct {
 	// Alias we want to lookup
 	Alias string `json:"alias"`
+	// Should we ask appservices for their aliases as a part of
+	// the request?
+	IncludeAppservices bool `json:"include_appservices"`
 }
 
 // GetRoomIDForAliasResponse is a response to GetRoomIDForAlias
diff --git a/roomserver/internal/alias.go b/roomserver/internal/alias.go
index 843b0bcc..f15881d7 100644
--- a/roomserver/internal/alias.go
+++ b/roomserver/internal/alias.go
@@ -88,31 +88,35 @@ func (r *RoomserverInternalAPI) GetRoomIDForAlias(
 ) error {
 	// Look up the room ID in the database
 	roomID, err := r.DB.GetRoomIDForAlias(ctx, request.Alias)
-	if err != nil {
-		return err
+	if err == nil && roomID != "" {
+		response.RoomID = roomID
+		return nil
 	}
 
-	if r.asAPI != nil { // appservice component is wired in
-		if roomID == "" {
-			// No room found locally, try our application services by making a call to
-			// the appservice component
-			aliasReq := asAPI.RoomAliasExistsRequest{Alias: request.Alias}
-			var aliasResp asAPI.RoomAliasExistsResponse
-			if err = r.asAPI.RoomAliasExists(ctx, &aliasReq, &aliasResp); err != nil {
+	// Check appservice on err, but only if the appservice API is
+	// wired in and no room ID was found.
+	if r.asAPI != nil && request.IncludeAppservices && roomID == "" {
+		// No room found locally, try our application services by making a call to
+		// the appservice component
+		aliasReq := &asAPI.RoomAliasExistsRequest{
+			Alias: request.Alias,
+		}
+		aliasRes := &asAPI.RoomAliasExistsResponse{}
+		if err = r.asAPI.RoomAliasExists(ctx, aliasReq, aliasRes); err != nil {
+			return err
+		}
+
+		if aliasRes.AliasExists {
+			roomID, err = r.DB.GetRoomIDForAlias(ctx, request.Alias)
+			if err != nil {
 				return err
 			}
-
-			if aliasResp.AliasExists {
-				roomID, err = r.DB.GetRoomIDForAlias(ctx, request.Alias)
-				if err != nil {
-					return err
-				}
-			}
+			response.RoomID = roomID
+			return nil
 		}
 	}
 
-	response.RoomID = roomID
-	return nil
+	return err
 }
 
 // GetAliasesForRoomID implements alias.RoomserverInternalAPI
diff --git a/roomserver/internal/api.go b/roomserver/internal/api.go
index e10bdb46..5b8959b0 100644
--- a/roomserver/internal/api.go
+++ b/roomserver/internal/api.go
@@ -89,6 +89,7 @@ func (r *RoomserverInternalAPI) SetFederationSenderAPI(fsAPI fsAPI.FederationSen
 		Cfg:        r.Cfg,
 		DB:         r.DB,
 		FSAPI:      r.fsAPI,
+		RSAPI:      r,
 		Inputer:    r.Inputer,
 	}
 	r.Peeker = &perform.Peeker{
diff --git a/roomserver/internal/perform/perform_join.go b/roomserver/internal/perform/perform_join.go
index 453901fc..ada584a8 100644
--- a/roomserver/internal/perform/perform_join.go
+++ b/roomserver/internal/perform/perform_join.go
@@ -24,6 +24,7 @@ import (
 	fsAPI "github.com/matrix-org/dendrite/federationsender/api"
 	"github.com/matrix-org/dendrite/internal/eventutil"
 	"github.com/matrix-org/dendrite/roomserver/api"
+	rsAPI "github.com/matrix-org/dendrite/roomserver/api"
 	"github.com/matrix-org/dendrite/roomserver/internal/helpers"
 	"github.com/matrix-org/dendrite/roomserver/internal/input"
 	"github.com/matrix-org/dendrite/roomserver/storage"
@@ -36,6 +37,7 @@ type Joiner struct {
 	ServerName gomatrixserverlib.ServerName
 	Cfg        *config.RoomServer
 	FSAPI      fsAPI.FederationSenderInternalAPI
+	RSAPI      rsAPI.RoomserverInternalAPI
 	DB         storage.Database
 
 	Inputer *input.Inputer
@@ -121,11 +123,17 @@ func (r *Joiner) performJoinRoomByAlias(
 		roomID = dirRes.RoomID
 		req.ServerNames = append(req.ServerNames, dirRes.ServerNames...)
 	} else {
+		var getRoomReq = rsAPI.GetRoomIDForAliasRequest{
+			Alias:              req.RoomIDOrAlias,
+			IncludeAppservices: true,
+		}
+		var getRoomRes = rsAPI.GetRoomIDForAliasResponse{}
 		// Otherwise, look up if we know this room alias locally.
-		roomID, err = r.DB.GetRoomIDForAlias(ctx, req.RoomIDOrAlias)
+		err = r.RSAPI.GetRoomIDForAlias(ctx, &getRoomReq, &getRoomRes)
 		if err != nil {
 			return "", "", fmt.Errorf("Lookup room alias %q failed: %w", req.RoomIDOrAlias, err)
 		}
+		roomID = getRoomRes.RoomID
 	}
 
 	// If the room ID is empty then we failed to look up the alias.