diff --git a/Linphone/core/participant/ParticipantDeviceCore.cpp b/Linphone/core/participant/ParticipantDeviceCore.cpp
index 433a9231..6a630131 100644
--- a/Linphone/core/participant/ParticipantDeviceCore.cpp
+++ b/Linphone/core/participant/ParticipantDeviceCore.cpp
@@ -68,7 +68,7 @@ ParticipantDeviceCore::ParticipantDeviceCore(const std::shared_ptr<linphone::Par
 }
 
 ParticipantDeviceCore::~ParticipantDeviceCore() {
-	mParticipantDeviceModel->removeListener();
+	if (mParticipantDeviceModel) mParticipantDeviceModel->removeListener();
 }
 
 void ParticipantDeviceCore::setSelf(QSharedPointer<ParticipantDeviceCore> me) {
diff --git a/Linphone/model/conference/ConferenceModel.cpp b/Linphone/model/conference/ConferenceModel.cpp
index 82701edd..9f986c85 100644
--- a/Linphone/model/conference/ConferenceModel.cpp
+++ b/Linphone/model/conference/ConferenceModel.cpp
@@ -171,7 +171,7 @@ bool ConferenceModel::isScreenSharingEnabled() const {
 void ConferenceModel::onActiveSpeakerParticipantDevice(
     const std::shared_ptr<linphone::Conference> &conference,
     const std::shared_ptr<const linphone::ParticipantDevice> &participantDevice) {
-	lDebug() << "onActiveSpeakerParticipantDevice: " << participantDevice->getAddress()->asString().c_str();
+    lDebug() << "onActiveSpeakerParticipantDevice: " << (participantDevice ? participantDevice->getAddress()->asString().c_str() : "NULL");
 
 	emit activeSpeakerParticipantDevice(conference, conference->getActiveSpeakerParticipantDevice());
 }