diff --git a/telegram/utils.go b/telegram/utils.go
index 935beb7..d32d69d 100644
--- a/telegram/utils.go
+++ b/telegram/utils.go
@@ -648,6 +648,13 @@ func (c *Client) sendMUCSubject(chatID int64, resource string) {
 
 // GetMUCNickname generates a unique nickname for a MUC member
 func (c *Client) GetMUCNickname(chatID int64) string {
+	if chatID == 0 {
+		if c.me != nil {
+			chatID = c.me.Id
+		} else {
+			return "me"
+		}
+	}
 	return c.FormatContact(chatID)
 }
 
diff --git a/xmpp/handlers.go b/xmpp/handlers.go
index a82d315..7a499e7 100644
--- a/xmpp/handlers.go
+++ b/xmpp/handlers.go
@@ -847,6 +847,7 @@ func handleGetDiscoInfo(s xmpp.Sender, iq *stanza.IQ, di *stanza.DiscoInfo) {
 							"muc_nonanonymous",
 							"muc_unsecured",
 							"http://jabber.org/protocol/muc#stable_id",
+							"jabber:iq:register",
 						)
 						fields := []*stanza.Field{
 							&stanza.Field{
@@ -995,33 +996,56 @@ func handleGetQueryRegister(s xmpp.Sender, iq *stanza.IQ) {
 	}
 	defer gateway.ResumableSend(component, answer)
 
-	var login string
+	_, toOk, toIsGroup := toToID(iq.To)
+
 	bare, _, ok := gateway.SplitJID(iq.From)
+	var session *telegram.Client
+	var sessionOk bool
 	if ok {
-		session, ok := sessions[bare]
-		if ok {
-			login = session.Session.Login
-		}
+		session, sessionOk = sessions[bare]
 	}
 
-	var query stanza.IQPayload
-	if login == "" {
-		query = extensions.QueryRegister{
-			Instructions: fmt.Sprintf("Authorization in Telegram is a multi-step process, so please accept %v to your contacts and follow further instructions (provide the authentication code there, etc.).\nFor now, please provide your login.", iq.To),
+	if toOk {
+		if toIsGroup {
+			nickname := "me"
+			if sessionOk {
+				nickname = session.GetMUCNickname(0)
+			}
+			answer.Payload = extensions.QueryRegister{
+				Instructions: "MUC username is static",
+				Username:     nickname,
+				Registered:   &extensions.QueryRegisterRegistered{},
+			}
+		} else {
+			query := extensions.QueryRegister{}
+			iqAnswerSetError(answer, &query, 404)
+			return
 		}
 	} else {
-		query = extensions.QueryRegister{
-			Instructions: "Already logged in",
-			Username:     login,
-			Registered:   &extensions.QueryRegisterRegistered{},
+		var login string
+		if sessionOk {
+			login = session.Session.Login
 		}
-	}
-	answer.Payload = query
 
-	log.Debugf("%#v", query)
+		var query stanza.IQPayload
+		if login == "" {
+			query = extensions.QueryRegister{
+				Instructions: fmt.Sprintf("Authorization in Telegram is a multi-step process, so please accept %v to your contacts and follow further instructions (provide the authentication code there, etc.).\nFor now, please provide your login.", iq.To),
+			}
+		} else {
+			query = extensions.QueryRegister{
+				Instructions: "Already logged in",
+				Username:     login,
+				Registered:   &extensions.QueryRegisterRegistered{},
+			}
+		}
+		answer.Payload = query
 
-	if login == "" {
-		gateway.SubscribeToTransport(component, iq.From)
+		log.Debugf("%#v", query)
+
+		if login == "" {
+			gateway.SubscribeToTransport(component, iq.From)
+		}
 	}
 }
 
@@ -1032,6 +1056,12 @@ func handleSetQueryRegister(s xmpp.Sender, iq *stanza.IQ, query *extensions.Quer
 	}
 	defer gateway.ResumableSend(component, answer)
 
+	_, toOk, _ := toToID(iq.To)
+	if toOk {
+		iqAnswerSetError(answer, query, 400)
+		return
+	}
+
 	if query.Remove != nil {
 		iqAnswerSetError(answer, query, 405)
 		return
@@ -1477,6 +1507,13 @@ func iqAnswerSetError(answer *stanza.IQ, payload *extensions.QueryRegister, code
 			Type:   stanza.ErrorTypeModify,
 			Reason: "bad-request",
 		}
+	case 404:
+		answer.Error = &stanza.Err{
+			Code:   code,
+			Type:   stanza.ErrorTypeCancel,
+			Reason: "item-not-found",
+			Text:   "No such room",
+		}
 	case 405:
 		answer.Error = &stanza.Err{
 			Code:   code,