diff --git a/CHANGES b/CHANGES
index 62f6daa64..6caf301f1 100644
--- a/CHANGES
+++ b/CHANGES
@@ -28,6 +28,7 @@ Misc:
  - Qt: Clean up cheats dialog
  - Qt: Only set default controller bindings if loading fails (fixes mgba.io/i/799)
  - Qt: Save converter now supports importing GameShark Advance saves
+ - Qt: Save positions of multiplayer windows (closes mgba.io/i/2128)
 
 0.9.3: (2021-12-17)
 Emulation fixes:
diff --git a/src/platform/qt/GBAApp.cpp b/src/platform/qt/GBAApp.cpp
index 7d4252841..466cefa9f 100644
--- a/src/platform/qt/GBAApp.cpp
+++ b/src/platform/qt/GBAApp.cpp
@@ -120,7 +120,7 @@ Window* GBAApp::newWindow() {
 	if (m_windows.count() >= MAX_GBAS) {
 		return nullptr;
 	}
-	Window* w = new Window(&m_manager, m_configController, m_multiplayer.attached());
+	Window* w = new Window(&m_manager, m_configController, m_windows.count());
 	connect(w, &Window::destroyed, [this, w]() {
 		m_windows.removeAll(w);
 		for (Window* w : m_windows) {
diff --git a/src/platform/qt/Window.cpp b/src/platform/qt/Window.cpp
index a57106152..ef47b4945 100644
--- a/src/platform/qt/Window.cpp
+++ b/src/platform/qt/Window.cpp
@@ -88,6 +88,7 @@ Window::Window(CoreManager* manager, ConfigController* config, int playerId, QWi
 	, m_config(config)
 	, m_inputController(playerId, this)
 	, m_shortcutController(new ShortcutController(this))
+	, m_playerId(playerId)
 {
 	setFocusPolicy(Qt::StrongFocus);
 	setAcceptDrops(true);
@@ -217,6 +218,16 @@ void Window::resizeFrame(const QSize& size) {
 	}
 }
 
+void Window::updateMultiplayerStatus(bool canOpenAnother) {
+	m_multiWindow->setEnabled(canOpenAnother);
+	if (m_controller) {
+		MultiplayerController* multiplayer = m_controller->multiplayerController();
+		if (multiplayer) {
+			m_playerId = multiplayer->playerId(m_controller.get());
+		}
+	}
+}
+
 void Window::updateMultiplayerActive(bool active) {
 	m_multiActive = active;
 	updateMute();
@@ -678,7 +689,7 @@ void Window::showEvent(QShowEvent* event) {
 	}
 	m_wasOpened = true;
 	resizeFrame(m_screenWidget->sizeHint());
-	QVariant windowPos = m_config->getQtOption("windowPos");
+	QVariant windowPos = m_config->getQtOption("windowPos", m_playerId > 0 ? QString("player%0").arg(m_playerId) : QString());
 	bool maximized = m_config->getQtOption("maximized").toBool();
 	QRect geom = windowHandle()->screen()->availableGeometry();
 	if (!windowPos.isNull() && geom.contains(windowPos.toPoint())) {
@@ -719,7 +730,7 @@ void Window::hideEvent(QHideEvent* event) {
 
 void Window::closeEvent(QCloseEvent* event) {
 	emit shutdown();
-	m_config->setQtOption("windowPos", pos());
+	m_config->setQtOption("windowPos", pos(), m_playerId > 0 ? QString("player%0").arg(m_playerId) : QString());
 	m_config->setQtOption("maximized", isMaximized());
 
 	if (m_savedScale > 0) {
@@ -1098,7 +1109,7 @@ void Window::updateTitle(float fps) {
 
 		MultiplayerController* multiplayer = m_controller->multiplayerController();
 		if (multiplayer && multiplayer->attached() > 1) {
-			title += tr(" -  Player %1 of %2").arg(multiplayer->playerId(m_controller.get()) + 1).arg(multiplayer->attached());
+			title += tr(" -  Player %1 of %2").arg(m_playerId + 1).arg(multiplayer->attached());
 			for (Action* action : m_nonMpActions) {
 				action->setEnabled(false);
 			}
@@ -2023,7 +2034,7 @@ void Window::updateMute() {
 		QString multiplayerAudio = m_config->getQtOption("multiplayerAudio").toString();
 		if (multiplayerAudio == QLatin1String("p1")) {
 			MultiplayerController* multiplayer = m_controller->multiplayerController();
-			mute = multiplayer && multiplayer->attached() > 1 && multiplayer->playerId(m_controller.get());
+			mute = multiplayer && multiplayer->attached() > 1 && m_playerId;
 		} else if (multiplayerAudio == QLatin1String("active")) {
 			mute = !m_multiActive;
 		}
diff --git a/src/platform/qt/Window.h b/src/platform/qt/Window.h
index 6d93948a1..a99a882b5 100644
--- a/src/platform/qt/Window.h
+++ b/src/platform/qt/Window.h
@@ -63,7 +63,7 @@ public:
 
 	void resizeFrame(const QSize& size);
 
-	void updateMultiplayerStatus(bool canOpenAnother) { m_multiWindow->setEnabled(canOpenAnother); }
+	void updateMultiplayerStatus(bool canOpenAnother);
 	void updateMultiplayerActive(bool active);
 
 signals:
@@ -230,6 +230,7 @@ private:
 
 	bool m_inactiveMute = false;
 	bool m_multiActive = true;
+	int m_playerId;
 
 	std::unique_ptr<OverrideView> m_overrideView;
 	std::unique_ptr<SensorView> m_sensorView;