diff --git a/runners/windows/windowsrunner.h b/runners/windows/windowsrunner.h
--- a/runners/windows/windowsrunner.h
+++ b/runners/windows/windowsrunner.h
@@ -63,7 +63,6 @@
         QMutex m_mutex;
 
         bool m_inSession : 1; // only used in the main thread
-        bool m_ready : 1; // protected by m_mutex
 };
 
 #endif // WINDOWSRUNNER_H
diff --git a/runners/windows/windowsrunner.cpp b/runners/windows/windowsrunner.cpp
--- a/runners/windows/windowsrunner.cpp
+++ b/runners/windows/windowsrunner.cpp
@@ -37,8 +37,7 @@
 
 WindowsRunner::WindowsRunner(QObject* parent, const QVariantList& args)
     : AbstractRunner(parent, args),
-      m_inSession(false),
-      m_ready(false)
+      m_inSession(false)
 {
     Q_UNUSED(args)
     setObjectName( QLatin1String("Windows") );
@@ -70,7 +69,6 @@
 // Called in the main thread
 void WindowsRunner::gatherInfo()
 {
-    QMutexLocker locker(&m_mutex);
     if (!m_inSession) {
         return;
     }
@@ -101,36 +99,34 @@
         m_desktopNames << KWindowSystem::desktopName(i);
     }
 
-    m_ready = true;
+    // unlock lock locked in prepareForMatchSession
+    m_mutex.unlock();
 }
 
 // Called in the main thread
 void WindowsRunner::prepareForMatchSession()
 {
-    QMutexLocker locker(&m_mutex);
+    // gatherInfo will unlock the lock
+    m_mutex.lock();
     m_inSession = true;
-    m_ready = false;
     QTimer::singleShot(0, this, &WindowsRunner::gatherInfo);
 }
 
 // Called in the main thread
 void WindowsRunner::matchSessionComplete()
 {
     QMutexLocker locker(&m_mutex);
     m_inSession = false;
-    m_ready = false;
     m_desktopNames.clear();
     m_icons.clear();
     m_windows.clear();
 }
 
 // Called in the secondary thread
 void WindowsRunner::match(Plasma::RunnerContext& context)
 {
+    // will run block as long as gatherInfo has not finished
     QMutexLocker locker(&m_mutex);
-    if (!m_ready) {
-        return;
-    }
 
     QString term = context.query();