diff --git a/AdaptiveBrightness/AdaptiveBrightness.ui b/AdaptiveBrightness/AdaptiveBrightness.ui
index f09d374..5d19ddb 100644
--- a/AdaptiveBrightness/AdaptiveBrightness.ui
+++ b/AdaptiveBrightness/AdaptiveBrightness.ui
@@ -6,8 +6,8 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>600</width>
-    <height>400</height>
+    <width>406</width>
+    <height>306</height>
    </rect>
   </property>
   <property name="windowTitle">
@@ -17,13 +17,35 @@
    <iconset resource="AdaptiveBrightness.qrc">
     <normaloff>:/AdaptiveBrightness/resources/system.ico</normaloff>:/AdaptiveBrightness/resources/system.ico</iconset>
   </property>
-  <widget class="QWidget" name="centralWidget"/>
+  <widget class="QWidget" name="centralWidget">
+   <layout class="QFormLayout" name="formLayout_2">
+    <item row="0" column="1">
+     <widget class="QGroupBox" name="groupBox">
+      <property name="title">
+       <string>Manual brightness control</string>
+      </property>
+      <layout class="QGridLayout" name="gridLayout">
+       <item row="0" column="0">
+        <widget class="QSlider" name="horizontalSlider">
+         <property name="toolTip">
+          <string>Brightness</string>
+         </property>
+         <property name="orientation">
+          <enum>Qt::Horizontal</enum>
+         </property>
+        </widget>
+       </item>
+      </layout>
+     </widget>
+    </item>
+   </layout>
+  </widget>
   <widget class="QMenuBar" name="menuBar">
    <property name="geometry">
     <rect>
      <x>0</x>
      <y>0</y>
-     <width>600</width>
+     <width>406</width>
      <height>21</height>
     </rect>
    </property>
diff --git a/AdaptiveBrightness/main_window.cpp b/AdaptiveBrightness/main_window.cpp
index b1fb0a9..a5cb12a 100644
--- a/AdaptiveBrightness/main_window.cpp
+++ b/AdaptiveBrightness/main_window.cpp
@@ -5,6 +5,8 @@
 
 #include <cmath>
 
+#include <QGroupBox>
+#include <QSlider>
 #include <QtDebug>
 #include <QtGlobal>
 
@@ -18,6 +20,16 @@ MainWindow::MainWindow(QWidget* parent) : QMainWindow(parent)
     qDebug(ltr("Creating main window"));
 
     m_ui.setupUi(this);
+    auto slider = m_ui.centralWidget->findChild<QGroupBox*>("groupBox")->findChild<QSlider*>("horizontalSlider");
+
+    if(slider) {
+        connect(slider, &QSlider::valueChanged, [this](int value) {
+            const auto mappedBrightness = utils::map(value, 0, 100, 0.f, 1.f);
+            const auto newBrightness = std::clamp(mappedBrightness, 0.f, 1.f);
+            qDebug(ltr("Overriding brightness with %1").arg(newBrightness));
+            m_brightness = newBrightness;
+        });
+    }
 
     loadIcons();