diff --git a/src/address/address.h b/src/address/address.h
index 86549e8f9..134f7601b 100644
--- a/src/address/address.h
+++ b/src/address/address.h
@@ -32,6 +32,7 @@ class LINPHONE_PUBLIC Address : public ClonableObject {
 	// TODO: Remove me later.
 	friend class CallSession;
 	friend class ClientGroupChatRoom;
+	friend class ClientGroupChatRoomPrivate;
 
 public:
 	Address (const std::string &address = "");
diff --git a/src/chat/client-group-chat-room-p.h b/src/chat/client-group-chat-room-p.h
index 346faf869..416dd29b0 100644
--- a/src/chat/client-group-chat-room-p.h
+++ b/src/chat/client-group-chat-room-p.h
@@ -29,11 +29,15 @@
 
 LINPHONE_BEGIN_NAMESPACE
 
+class CallSession;
+
 class ClientGroupChatRoomPrivate : public ChatRoomPrivate {
 public:
 	ClientGroupChatRoomPrivate (LinphoneCore *core);
 	virtual ~ClientGroupChatRoomPrivate () = default;
 
+	std::shared_ptr<CallSession> createSession ();
+
 private:
 	L_DECLARE_PUBLIC(ClientGroupChatRoom);
 };
diff --git a/src/chat/client-group-chat-room.cpp b/src/chat/client-group-chat-room.cpp
index 30753dbed..7afe7c70e 100644
--- a/src/chat/client-group-chat-room.cpp
+++ b/src/chat/client-group-chat-room.cpp
@@ -34,6 +34,21 @@ LINPHONE_BEGIN_NAMESPACE
 ClientGroupChatRoomPrivate::ClientGroupChatRoomPrivate (LinphoneCore *core)
 	: ChatRoomPrivate(core) {}
 
+// -----------------------------------------------------------------------------
+
+shared_ptr<CallSession> ClientGroupChatRoomPrivate::createSession () {
+	L_Q();
+	CallSessionParams csp;
+	csp.addCustomHeader("Require", "recipient-list-invite");
+	shared_ptr<CallSession> session = q->focus->getPrivate()->createSession(*q, &csp, false, q);
+	session->configure(LinphoneCallOutgoing, nullptr, nullptr, q->me->getAddress(), q->focus->getAddress());
+	session->initiateOutgoing();
+	Address addr = q->me->getAddress();
+	addr.setParam("text");
+	session->getPrivate()->getOp()->set_contact_address(addr.getPrivate()->getInternalAddress());
+	return session;
+}
+
 // =============================================================================
 
 ClientGroupChatRoom::ClientGroupChatRoom (LinphoneCore *core, const Address &me, const string &subject)
@@ -55,28 +70,27 @@ void ClientGroupChatRoom::addParticipants (const list<Address> &addresses, const
 	L_D();
 	if (addresses.empty())
 		return;
+	if ((d->state != ChatRoom::State::Instantiated) && (d->state != ChatRoom::State::Created)) {
+		lError() << "Cannot add participants to the ClientGroupChatRoom in a state other than Instantiated or Created";
+		return;
+	}
 	list<Address> sortedAddresses(addresses);
 	sortedAddresses.sort();
 	sortedAddresses.unique();
-	if (d->state == ChatRoom::State::Instantiated) {
-		Content content;
-		content.setBody(getResourceLists(sortedAddresses));
-		content.setContentType("application/resource-lists+xml");
-		content.setContentDisposition("recipient-list");
-		CallSessionParams csp;
-		if (params)
-			csp = *params;
-		csp.addCustomHeader("Require", "recipient-list-invite");
-		shared_ptr<CallSession> session = focus->getPrivate()->createSession(*this, &csp, false, this);
-		session->configure(LinphoneCallOutgoing, nullptr, nullptr, me->getAddress(), focus->getAddress());
-		session->initiateOutgoing();
-		Address addr = me->getAddress();
-		addr.setParam("text");
-		session->getPrivate()->getOp()->set_contact_address(addr.getPrivate()->getInternalAddress());
+	Content content;
+	content.setBody(getResourceLists(sortedAddresses));
+	content.setContentType("application/resource-lists+xml");
+	content.setContentDisposition("recipient-list");
+	shared_ptr<CallSession> session = focus->getPrivate()->getSession();
+	if (session)
+		session->update(nullptr, subject, &content);
+	else {
+		session = d->createSession();
 		session->startInvite(nullptr, subject, &content);
-		d->setState(ChatRoom::State::CreationPending);
+		if (d->state == ChatRoom::State::Instantiated) {
+			d->setState(ChatRoom::State::CreationPending);
+		}
 	}
-	// TODO
 }
 
 bool ClientGroupChatRoom::canHandleParticipants () const {
@@ -118,7 +132,12 @@ void ClientGroupChatRoom::setSubject (const string &subject) {
 		return;
 	}
 	shared_ptr<CallSession> session = focus->getPrivate()->getSession();
-	session->update(nullptr, subject);
+	if (session)
+		session->update(nullptr, subject);
+	else {
+		session = d->createSession();
+		session->startInvite(nullptr, subject, nullptr);
+	}
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/conference/participant.h b/src/conference/participant.h
index 0fbef9f00..37cbb24a1 100644
--- a/src/conference/participant.h
+++ b/src/conference/participant.h
@@ -35,6 +35,7 @@ class Participant : public Object {
 	friend class Call;
 	friend class CallPrivate;
 	friend class ClientGroupChatRoom;
+	friend class ClientGroupChatRoomPrivate;
 	friend class LocalConference;
 	friend class MediaSessionPrivate;
 	friend class RemoteConference;
diff --git a/src/conference/session/call-session.h b/src/conference/session/call-session.h
index dd8e27f2f..d09435a92 100644
--- a/src/conference/session/call-session.h
+++ b/src/conference/session/call-session.h
@@ -37,6 +37,7 @@ class Content;
 class LINPHONE_PUBLIC CallSession : public Object {
 	friend class CallPrivate;
 	friend class ClientGroupChatRoom;
+	friend class ClientGroupChatRoomPrivate;
 
 public:
 	L_OVERRIDE_SHARED_FROM_THIS(CallSession);