diff --git a/samples/voiceclient/client.cpp b/samples/voiceclient/client.cpp
index 91be166e2..7b3ae9dc6 100644
--- a/samples/voiceclient/client.cpp
+++ b/samples/voiceclient/client.cpp
@@ -5,8 +5,11 @@
 
 #include "client.h"
 #include "blackmisc/vaudiodevicelist.h"
+#include "blackmisc/avcallsignlist.h"
 
 using namespace BlackMisc::Voice;
+using namespace BlackMisc::Aviation;
+
 
 /*
  * Client
@@ -156,10 +159,10 @@ void Client::outputDevicesCmd(QTextStream & /** args **/)
 void Client::listCallsignsCmd(QTextStream &args)
 {
     Q_UNUSED(args)
-    QSet<QString> users = m_voiceClient->getVoiceRoomCallsings(BlackCore::IVoice::COM1);
-    foreach(QString user, users)
+    CCallsignList callsigns = m_voiceClient->getVoiceRoomCallsigns(BlackCore::IVoice::COM1);
+    foreach(CCallsign callsign, callsigns)
     {
-        std::cout << " " << user.toStdString() << std::endl;
+        std::cout << " " << callsign.toStdString() << std::endl;
     }
     printLinePrefix();
 }
@@ -200,13 +203,13 @@ void Client::audioStoppedStream(const BlackCore::IVoice::ComUnit comUnit)
     printLinePrefix();
 }
 
-void Client::userJoinedRoom(const QString &callsign)
+void Client::userJoinedRoom(const CCallsign &callsign)
 {
     std::cout << callsign.toStdString() << " joined the voice room." << std::endl;
     printLinePrefix();
 }
 
-void Client::userLeftRoom(const QString &callsign)
+void Client::userLeftRoom(const CCallsign &callsign)
 {
     std::cout << callsign.toStdString() << " left the voice room." << std::endl;
     printLinePrefix();
diff --git a/samples/voiceclient/client.h b/samples/voiceclient/client.h
index da9da4876..a1e34dcdc 100644
--- a/samples/voiceclient/client.h
+++ b/samples/voiceclient/client.h
@@ -49,8 +49,8 @@ private slots:
     void connectionStatusDisconnected();
     void audioStartedStream(const BlackCore::IVoice::ComUnit comUnit);
     void audioStoppedStream(const BlackCore::IVoice::ComUnit comUnit);
-    void userJoinedRoom(const QString &callsign);
-    void userLeftRoom(const QString &callsign);
+    void userJoinedRoom(const BlackMisc::Aviation::CCallsign &callsign);
+    void userLeftRoom(const BlackMisc::Aviation::CCallsign &callsign);
 
 private:
     QMap<QString, std::function<void(QTextStream &)>> m_commands;