diff --git a/AdaptiveBrightness/main_window.cpp b/AdaptiveBrightness/main_window.cpp
index fe31789..1c773d1 100644
--- a/AdaptiveBrightness/main_window.cpp
+++ b/AdaptiveBrightness/main_window.cpp
@@ -61,6 +61,8 @@ void MainWindow::enumSensors()
 
 void MainWindow::enumMonitors()
 {
+    m_mtx.lock();
+
     m_ui.monitorDropdown->clear();
 
     auto monitors = enumerateMonitors();
@@ -70,6 +72,8 @@ void MainWindow::enumMonitors()
         m_ui.monitorDropdown->addItem(monitor.getName());
         m_monitors.push_back({std::move(monitor), 0.f, 1.f, currentBrightness, false});
     }
+
+    m_mtx.unlock();
 }
 
 void MainWindow::loadIcons()
@@ -269,6 +273,8 @@ void MainWindow::updateCurrentMonitorGUI(int index)
 
 void MainWindow::updateState()
 {
+    m_mtx.lock();
+
     qDebug(ltr("Updating state"));
 
     bool sensorError = false;
@@ -322,6 +328,8 @@ void MainWindow::updateState()
     if(m_trayIcon) {
         m_trayIcon->setToolTip(tr("AdaptiveBrightness - %1%").arg(brightness * 100, 0, 'f', 0));
     }
+
+    m_mtx.unlock();
 }
 
 bool MainWindow::setMonitorBrightness(float& brightness)
diff --git a/AdaptiveBrightness/main_window.hpp b/AdaptiveBrightness/main_window.hpp
index dd7608e..7383aed 100644
--- a/AdaptiveBrightness/main_window.hpp
+++ b/AdaptiveBrightness/main_window.hpp
@@ -8,6 +8,7 @@
 #include <QIcon>
 #include <QMainWindow>
 #include <QMenu>
+#include <QMutex>
 #include <QSlider>
 #include <QSystemTrayIcon>
 #include <QThread>
@@ -63,6 +64,7 @@ class MainWindow : public QMainWindow {
 
     QThread* m_timerThread = nullptr;
     QTimer* m_timer = nullptr;
+    QMutex m_mtx;
 
     struct SensorData {
         Sensor driver;