diff --git a/internal/backend.go b/internal/backend.go
index e64c8ad..3de33c6 100644
--- a/internal/backend.go
+++ b/internal/backend.go
@@ -22,6 +22,7 @@ type Room interface {
 	AliasName() string
 	Name() string
 	Topic() string
+	SetTopic(user User, topic string) *models.ApiError
 	Events() []rooms.Event
 }
 
diff --git a/internal/backends/memory/rooms.go b/internal/backends/memory/rooms.go
index f0c6615..3b21e19 100644
--- a/internal/backends/memory/rooms.go
+++ b/internal/backends/memory/rooms.go
@@ -3,6 +3,8 @@ package memory
 import (
 	"sync"
 
+	"github.com/nxshock/signaller/internal/models"
+
 	"github.com/nxshock/signaller/internal"
 	"github.com/nxshock/signaller/internal/models/createroom"
 	"github.com/nxshock/signaller/internal/models/rooms"
@@ -77,3 +79,16 @@ func (room *Room) NewEvent(event rooms.Event) {
 
 	room.events = append(room.events, event)
 }
+
+func (room *Room) SetTopic(user internal.User, topic string) *models.ApiError {
+	room.mutex.Lock()
+	defer room.mutex.Unlock()
+
+	if room.creator.ID() != user.ID() { // TODO: currently only creator can change topic
+		return internal.NewError(models.M_FORBIDDEN, "")
+	}
+
+	room.topic = topic
+
+	return nil
+}
diff --git a/internal/backends/memory/rooms_test.go b/internal/backends/memory/rooms_test.go
index a844355..8d9dc33 100644
--- a/internal/backends/memory/rooms_test.go
+++ b/internal/backends/memory/rooms_test.go
@@ -62,3 +62,39 @@ func TestCreateAlreadyExistingRoom(t *testing.T) {
 	_, err = backend.CreateRoom(user, request)
 	assert.NotNil(t, err)
 }
+
+func TestSetRoomTopic(t *testing.T) {
+	backend := NewBackend("localhost")
+
+	user, _, _ := backend.Register("user1", "", "")
+
+	request := createroom.Request{
+		RoomAliasName: "room1",
+		Name:          "room1",
+		Topic:         "topic"}
+
+	room, _ := backend.CreateRoom(user, request)
+
+	var newTopic = "new topic"
+	err := room.SetTopic(user, newTopic)
+	assert.Nil(t, err)
+	assert.Equal(t, newTopic, room.Topic())
+}
+
+func TestSetRoomTopicWithnprivelegedUser(t *testing.T) {
+	backend := NewBackend("localhost")
+
+	creator, _, _ := backend.Register("user1", "", "")
+	user2, _, _ := backend.Register("user2", "", "")
+
+	request := createroom.Request{
+		RoomAliasName: "room1",
+		Name:          "room1",
+		Topic:         "topic"}
+
+	room, _ := backend.CreateRoom(creator, request)
+
+	var newTopic = "new topic"
+	err := room.SetTopic(user2, newTopic)
+	assert.NotNil(t, err)
+}