diff --git a/Linphone/core/chat/ChatCore.cpp b/Linphone/core/chat/ChatCore.cpp
index 5b6d10ca8..5970a95c3 100644
--- a/Linphone/core/chat/ChatCore.cpp
+++ b/Linphone/core/chat/ChatCore.cpp
@@ -396,17 +396,17 @@ void ChatCore::setSelf(const QSharedPointer<ChatCore> &me) {
 		    }
 		    mChatModelConnection->invokeToCore([this, success] { emit participantAddressesChanged(success); });
 	    });
-	mChatModelConnection->makeConnectToCore(&ChatCore::lRemoveParticipantAtIndex, [this](int index) {
-		mChatModelConnection->invokeToModel([this, index]() { mChatModel->removeParticipantAtIndex(index); });
+	mChatModelConnection->makeConnectToCore(&ChatCore::lRemoveParticipant, [this](QString sipAddress) {
+		mChatModelConnection->invokeToModel([this, sipAddress]() { mChatModel->removeParticipant(sipAddress); });
 	});
 
 	mChatModelConnection->makeConnectToCore(&ChatCore::lSetParticipantsAddresses, [this](QStringList addresses) {
 		mChatModelConnection->invokeToModel([this, addresses]() { mChatModel->setParticipantAddresses(addresses); });
 	});
 
-	mChatModelConnection->makeConnectToCore(&ChatCore::lToggleParticipantAdminStatusAtIndex, [this](int index) {
+	mChatModelConnection->makeConnectToCore(&ChatCore::lToggleParticipantAdminStatus, [this](QString sipAddress) {
 		mChatModelConnection->invokeToModel(
-		    [this, index]() { mChatModel->toggleParticipantAdminStatusAtIndex(index); });
+		    [this, sipAddress]() { mChatModel->toggleParticipantAdminStatus(sipAddress); });
 	});
 
 	mCoreModelConnection = SafeConnection<ChatCore, CoreModel>::create(me, CoreModel::getInstance());
diff --git a/Linphone/core/chat/ChatCore.hpp b/Linphone/core/chat/ChatCore.hpp
index cdea6e163..0491400bf 100644
--- a/Linphone/core/chat/ChatCore.hpp
+++ b/Linphone/core/chat/ChatCore.hpp
@@ -192,9 +192,9 @@ signals:
 	void lSetMuted(bool muted);
 	void lSetEphemeralLifetime(int time);
 	void lSetSubject(QString subject);
-	void lRemoveParticipantAtIndex(int index);
+	void lRemoveParticipant(QString sipAddress);
 	void lSetParticipantsAddresses(QStringList addresses);
-	void lToggleParticipantAdminStatusAtIndex(int index);
+	void lToggleParticipantAdminStatus(QString sipAddress);
 
 private:
 	QString id;
diff --git a/Linphone/model/chat/ChatModel.cpp b/Linphone/model/chat/ChatModel.cpp
index 00a14fcbc..f34805b14 100644
--- a/Linphone/model/chat/ChatModel.cpp
+++ b/Linphone/model/chat/ChatModel.cpp
@@ -221,14 +221,19 @@ void ChatModel::setSubject(QString subject) const {
 	return mMonitor->setSubject(Utils::appStringToCoreString(subject));
 }
 
-void ChatModel::removeParticipantAtIndex(int index) const {
-	auto participant = *std::next(mMonitor->getParticipants().begin(), index);
-	mMonitor->removeParticipant(participant);
+void ChatModel::removeParticipant(const QString &sipAddress) const {
+	if (!mMonitor) return;
+	auto addr = Utils::appStringToCoreString(sipAddress);
+	for (auto &p : mMonitor->getParticipants())
+		if (p && p->getAddress()->asStringUriOnly() == addr) return mMonitor->removeParticipant(p);
 }
 
-void ChatModel::toggleParticipantAdminStatusAtIndex(int index) const {
-	auto participant = *std::next(mMonitor->getParticipants().begin(), index);
-	mMonitor->setParticipantAdminStatus(participant, !participant->isAdmin());
+void ChatModel::toggleParticipantAdminStatus(const QString &sipAddress) const {
+	if (!mMonitor) return;
+	auto addr = Utils::appStringToCoreString(sipAddress);
+	for (auto &p : mMonitor->getParticipants())
+		if (p && p->getAddress()->asStringUriOnly() == addr)
+			return mMonitor->setParticipantAdminStatus(p, !p->isAdmin());
 }
 
 void ChatModel::setParticipantAddresses(const QStringList &addresses) {
diff --git a/Linphone/model/chat/ChatModel.hpp b/Linphone/model/chat/ChatModel.hpp
index 2c24d6b41..10ce89bf8 100644
--- a/Linphone/model/chat/ChatModel.hpp
+++ b/Linphone/model/chat/ChatModel.hpp
@@ -81,9 +81,9 @@ public:
 	void setMuted(bool muted);
 	void setEphemeralLifetime(int time);
 	void setSubject(QString subject) const;
-	void removeParticipantAtIndex(int index) const;
+	void removeParticipant(const QString &sipAddress) const;
 	void setParticipantAddresses(const QStringList &addresses);
-	void toggleParticipantAdminStatusAtIndex(int index) const;
+	void toggleParticipantAdminStatus(const QString &sipAddress) const;
 
 signals:
 	void historyDeleted();
diff --git a/Linphone/view/Page/Layout/Chat/GroupChatInfoParticipants.qml b/Linphone/view/Page/Layout/Chat/GroupChatInfoParticipants.qml
index 575573528..897334a83 100644
--- a/Linphone/view/Page/Layout/Chat/GroupChatInfoParticipants.qml
+++ b/Linphone/view/Page/Layout/Chat/GroupChatInfoParticipants.qml
@@ -144,7 +144,7 @@ ColumnLayout {
 									icon.height: Utils.getSizeWithScreenRatio(32)
 									onClicked: {
 										detailOptions.close()
-										mainItem.chatGui.core.lToggleParticipantAdminStatusAtIndex(index)
+										mainItem.chatGui.core.lToggleParticipantAdminStatus(participantGui.core.sipAddress)
 									}
 								}
 								IconLabelButton {
@@ -181,7 +181,7 @@ ColumnLayout {
 										"",
 										function(confirmed) {
 											if (confirmed) {
-												mainItem.chatGui.core.lRemoveParticipantAtIndex(index)
+												mainItem.chatGui.core.lRemoveParticipant(participantGui.core.sipAddress)
 											}
 										})
 									}