diff --git a/telegram/muc.go b/telegram/muc.go
index 4f718d9..0470f7d 100644
--- a/telegram/muc.go
+++ b/telegram/muc.go
@@ -52,6 +52,7 @@ func NewMUCState() *MUCState {
 
 type MUCOccupantsLRU struct {
 	m      map[int64]*MUCOccupant
+	rev    map[string]int64
 	oldest *MUCOccupant
 	newest *MUCOccupant
 	lock   sync.Mutex
@@ -59,7 +60,8 @@ type MUCOccupantsLRU struct {
 
 func NewMUCOccupantsLRU() *MUCOccupantsLRU {
 	return &MUCOccupantsLRU{
-		m: make(map[int64]*MUCOccupant),
+		m:   make(map[int64]*MUCOccupant),
+		rev: make(map[string]int64),
 	}
 }
 
@@ -71,6 +73,14 @@ func (lru *MUCOccupantsLRU) Get(id int64) (*MUCOccupant, bool) {
 	return occupant, ok
 }
 
+func (lru *MUCOccupantsLRU) GetIdByNickname(nickname string) (int64, bool) {
+	lru.lock.Lock()
+	defer lru.lock.Unlock()
+
+	id, ok := lru.rev[nickname]
+	return id, ok
+}
+
 func (lru *MUCOccupantsLRU) cutOut(oldOccupant *MUCOccupant) (prev, next *MUCOccupant) {
 	prev, next = oldOccupant.cutOut()
 	if lru.oldest == oldOccupant {
@@ -102,6 +112,9 @@ func (lru *MUCOccupantsLRU) Set(id int64, occupant *MUCOccupant) (deleted *MUCOc
 
 	if oldOk {
 		lru.cutOut(oldOccupant)
+
+		delete(lru.rev, oldOccupant.Nickname)
+		lru.rev[occupant.Nickname] = id
 	}
 
 	if (lru.oldest == nil) != (lru.newest == nil) {
@@ -120,6 +133,7 @@ func (lru *MUCOccupantsLRU) Set(id int64, occupant *MUCOccupant) (deleted *MUCOc
 	if len(lru.m) > int(MUCOccupantsLimit) && lru.oldest != nil {
 		deleted = lru.oldest
 		delete(lru.m, lru.oldest.id)
+		delete(lru.rev, lru.oldest.Nickname)
 		lru.cutOut(lru.oldest)
 	}
 
@@ -136,6 +150,7 @@ func (lru *MUCOccupantsLRU) Delete(id int64) {
 
 	if oldOk {
 		lru.cutOut(oldOccupant)
+		delete(lru.rev, oldOccupant.Nickname)
 	}
 }
 
@@ -183,6 +198,7 @@ func (lru *MUCOccupantsLRU) Clear() {
 		occupant.next = nil
 	}
 	lru.m = make(map[int64]*MUCOccupant)
+	lru.rev = make(map[string]int64)
 
 	lru.oldest = nil
 	lru.newest = nil
diff --git a/telegram/utils.go b/telegram/utils.go
index 08f8d7e..c736f1c 100644
--- a/telegram/utils.go
+++ b/telegram/utils.go
@@ -984,7 +984,7 @@ func (c *Client) GetMyMUCNickname(chatID int64) (string, bool) {
 	return occupant.Nickname, true
 }
 
-// GetMUCMemberIdByNickname looks up the telegram ID by the MUC nickname (slow yet! (TODO))
+// GetMUCMemberIdByNickname looks up the telegram ID by the MUC nickname
 func (c *Client) GetMUCMemberIdByNickname(chatID int64, nickname string) int64 {
 	c.locks.mucCacheLock.Lock()
 	defer c.locks.mucCacheLock.Unlock()
@@ -994,10 +994,9 @@ func (c *Client) GetMUCMemberIdByNickname(chatID int64, nickname string) int64 {
 		return 0
 	}
 
-	for occupant := range mucState.Occupants.Range() {
-		if occupant.Nickname == nickname {
-			return occupant.id
-		}
+	id, ok := mucState.Occupants.GetIdByNickname(nickname)
+	if ok {
+		return id
 	}
 
 	return 0