diff --git a/AdaptiveBrightness/monitor.hpp b/AdaptiveBrightness/monitor.hpp
index 2ef8938..f887557 100644
--- a/AdaptiveBrightness/monitor.hpp
+++ b/AdaptiveBrightness/monitor.hpp
@@ -40,6 +40,7 @@ class Monitor {
     const PhysicalMonitor m_physicalMonitor;
 
     std::optional<std::pair<DWORD, DWORD>> m_brightnessRange;
+    bool m_errorOccurred = false;
 
     Monitor(HMONITOR hMonitor, PHYSICAL_MONITOR physicalMonitor);
 
diff --git a/AdaptiveBrightness/monitor_win.cpp b/AdaptiveBrightness/monitor_win.cpp
index d0e469d..57400b4 100644
--- a/AdaptiveBrightness/monitor_win.cpp
+++ b/AdaptiveBrightness/monitor_win.cpp
@@ -34,6 +34,8 @@ Monitor::~Monitor()
 
 bool Monitor::setBrightness(float percentage)
 {
+    m_errorOccurred = true;
+
     if(!m_brightnessRange) {
         qDebug(ltr("No brightness range known for monitor '%1' with handle '0x%2' and physical handle '0x%3'")
                    .arg(m_physicalMonitor.name)
@@ -62,11 +64,15 @@ bool Monitor::setBrightness(float percentage)
                .arg(reinterpret_cast<qulonglong>(m_physicalMonitor.handle), 0, 16)
                .arg(newBrightness));
 
+    m_errorOccurred = false;
+
     return true;
 }
 
 float Monitor::getBrightness()
 {
+    m_errorOccurred = true;
+
     qDebug(ltr("Getting brightness of monitor '%1' with handle '0x%2' and physical handle '0x%3'")
                .arg(m_physicalMonitor.name)
                .arg(reinterpret_cast<qulonglong>(m_hMonitor), 0, 16)
@@ -82,17 +88,19 @@ float Monitor::getBrightness()
                       .arg(reinterpret_cast<qulonglong>(m_hMonitor), 0, 16)
                       .arg(reinterpret_cast<qulonglong>(m_physicalMonitor.handle), 0, 16)
                       .arg(getLastErrorString()));
+
         return NAN;
     }
 
     m_brightnessRange = std::pair{minBrightness, maxBrightness};
+    m_errorOccurred = false;
 
     return std::clamp(map(brightness, minBrightness, maxBrightness, 0.f, 1.f), 0.f, 1.f);
 }
 
 Monitor::operator bool() const
 {
-    return false;
+    return !m_errorOccurred;
 }
 
 bool Monitor::hasBrightnessCapability() const