diff --git a/composite.cpp b/composite.cpp
index 36a424823c..e6cb0d484e 100644
--- a/composite.cpp
+++ b/composite.cpp
@@ -146,6 +146,8 @@ void Compositor::setup()
     }
 }
 
+extern int screen_number; // main.cpp
+
 void Compositor::slotCompositingOptionsInitialized()
 {
     char selection_name[ 100 ];
@@ -163,14 +165,15 @@ void Compositor::slotCompositingOptionsInitialized()
         // Some broken drivers crash on glXQuery() so to prevent constant KWin crashes:
         KSharedConfigPtr unsafeConfigPtr = KGlobal::config();
         KConfigGroup unsafeConfig(unsafeConfigPtr, "Compositing");
-        if (unsafeConfig.readEntry("OpenGLIsUnsafe", false))
+        const QString openGLIsUnsafe = "OpenGLIsUnsafe" + QString::number(screen_number);
+        if (unsafeConfig.readEntry(openGLIsUnsafe, false))
             kWarning(1212) << "KWin has detected that your OpenGL library is unsafe to use";
         else {
-            unsafeConfig.writeEntry("OpenGLIsUnsafe", true);
+            unsafeConfig.writeEntry(openGLIsUnsafe, true);
             unsafeConfig.sync();
 #ifndef KWIN_HAVE_OPENGLES
             if (!CompositingPrefs::hasGlx()) {
-                unsafeConfig.writeEntry("OpenGLIsUnsafe", false);
+                unsafeConfig.writeEntry(openGLIsUnsafe, false);
                 unsafeConfig.sync();
                 kDebug(1212) << "No glx extensions available";
                 break;
@@ -180,7 +183,7 @@ void Compositor::slotCompositingOptionsInitialized()
             m_scene = SceneOpenGL::createScene();
 
             // TODO: Add 30 second delay to protect against screen freezes as well
-            unsafeConfig.writeEntry("OpenGLIsUnsafe", false);
+            unsafeConfig.writeEntry(openGLIsUnsafe, false);
             unsafeConfig.sync();
 
             if (m_scene && !m_scene->initFailed())
diff --git a/tabbox/tabbox.cpp b/tabbox/tabbox.cpp
index cb2120f53f..0d23daa670 100644
--- a/tabbox/tabbox.cpp
+++ b/tabbox/tabbox.cpp
@@ -912,8 +912,9 @@ static bool areModKeysDepressed(const KShortcut& cut)
 
 void TabBox::navigatingThroughWindows(bool forward, const KShortcut& shortcut, TabBoxMode mode)
 {
-    if (isGrabbed())
+    if (!m_ready || isGrabbed() || !Workspace::self()->isOnCurrentHead()) {
         return;
+    }
     if (!options->focusPolicyIsReasonable()) {
         //ungrabXKeyboard(); // need that because of accelerator raw mode
         // CDE style raise / lower
@@ -931,75 +932,49 @@ void TabBox::navigatingThroughWindows(bool forward, const KShortcut& shortcut, T
 
 void TabBox::slotWalkThroughWindows()
 {
-    if (!m_ready){
-        return;
-    }
     navigatingThroughWindows(true, m_cutWalkThroughWindows, TabBoxWindowsMode);
 }
 
 void TabBox::slotWalkBackThroughWindows()
 {
-    if (!m_ready){
-        return;
-    }
     navigatingThroughWindows(false, m_cutWalkThroughWindowsReverse, TabBoxWindowsMode);
 }
 
 void TabBox::slotWalkThroughWindowsAlternative()
 {
-    if (!m_ready){
-        return;
-    }
     navigatingThroughWindows(true, m_cutWalkThroughWindowsAlternative, TabBoxWindowsAlternativeMode);
 }
 
 void TabBox::slotWalkBackThroughWindowsAlternative()
 {
-    if (!m_ready){
-        return;
-    }
     navigatingThroughWindows(false, m_cutWalkThroughWindowsAlternativeReverse, TabBoxWindowsAlternativeMode);
 }
 
 void TabBox::slotWalkThroughCurrentAppWindows()
 {
-    if (!m_ready){
-        return;
-    }
     navigatingThroughWindows(true, m_cutWalkThroughCurrentAppWindows, TabBoxCurrentAppWindowsMode);
 }
 
 void TabBox::slotWalkBackThroughCurrentAppWindows()
 {
-    if (!m_ready){
-        return;
-    }
     navigatingThroughWindows(false, m_cutWalkThroughCurrentAppWindowsReverse, TabBoxCurrentAppWindowsMode);
 }
 
 void TabBox::slotWalkThroughCurrentAppWindowsAlternative()
 {
-    if (!m_ready){
-        return;
-    }
     navigatingThroughWindows(true, m_cutWalkThroughCurrentAppWindowsAlternative, TabBoxCurrentAppWindowsAlternativeMode);
 }
 
 void TabBox::slotWalkBackThroughCurrentAppWindowsAlternative()
 {
-    if (!m_ready){
-        return;
-    }
     navigatingThroughWindows(false, m_cutWalkThroughCurrentAppWindowsAlternativeReverse, TabBoxCurrentAppWindowsAlternativeMode);
 }
 
 void TabBox::slotWalkThroughDesktops()
 {
-    if (!m_ready){
+    if (!m_ready || isGrabbed() || !Workspace::self()->isOnCurrentHead()) {
         return;
     }
-    if (isGrabbed())
-        return;
     if (areModKeysDepressed(m_cutWalkThroughDesktops)) {
         if (startWalkThroughDesktops())
             walkThroughDesktops(true);
@@ -1010,11 +985,9 @@ void TabBox::slotWalkThroughDesktops()
 
 void TabBox::slotWalkBackThroughDesktops()
 {
-    if (!m_ready){
+    if (!m_ready || isGrabbed() || !Workspace::self()->isOnCurrentHead()) {
         return;
     }
-    if (isGrabbed())
-        return;
     if (areModKeysDepressed(m_cutWalkThroughDesktopsReverse)) {
         if (startWalkThroughDesktops())
             walkThroughDesktops(false);
@@ -1025,11 +998,9 @@ void TabBox::slotWalkBackThroughDesktops()
 
 void TabBox::slotWalkThroughDesktopList()
 {
-    if (!m_ready){
+    if (!m_ready || isGrabbed() || !Workspace::self()->isOnCurrentHead()) {
         return;
     }
-    if (isGrabbed())
-        return;
     if (areModKeysDepressed(m_cutWalkThroughDesktopList)) {
         if (startWalkThroughDesktopList())
             walkThroughDesktops(true);
@@ -1040,11 +1011,9 @@ void TabBox::slotWalkThroughDesktopList()
 
 void TabBox::slotWalkBackThroughDesktopList()
 {
-    if (!m_ready){
+    if (!m_ready || isGrabbed() || !Workspace::self()->isOnCurrentHead()) {
         return;
     }
-    if (isGrabbed())
-        return;
     if (areModKeysDepressed(m_cutWalkThroughDesktopListReverse)) {
         if (startWalkThroughDesktopList())
             walkThroughDesktops(false);
diff --git a/workspace.cpp b/workspace.cpp
index 8f7e450d68..97d1f321c4 100644
--- a/workspace.cpp
+++ b/workspace.cpp
@@ -1606,6 +1606,34 @@ void Workspace::checkActiveScreen(const Client* c)
         active_screen = c->screen();
 }
 
+/**
+ * checks whether the X Window with the input focus is on our X11 screen
+ * if the window cannot be determined or inspected, resturn depends on whether there's actually
+ * more than one screen
+ *
+ * this is NOT in any way related to XRandR multiscreen
+ *
+ */
+extern bool is_multihead; // main.cpp
+bool Workspace::isOnCurrentHead()
+{
+    if (!is_multihead) {
+        return true;
+    }
+
+    Xcb::CurrentInput currentInput;
+    if (currentInput.window() == XCB_WINDOW_NONE) {
+        return !is_multihead;
+    }
+
+    Xcb::WindowGeometry geometry(currentInput.window());
+    if (geometry.isNull()) { // should not happen
+        return !is_multihead;
+    }
+
+    return rootWindow() == geometry->root;
+}
+
 /**
  * Called e.g. when a user clicks on a window, set active screen to be the screen
  * where the click occurred
diff --git a/workspace.h b/workspace.h
index d5b6342d35..e033ac9832 100644
--- a/workspace.h
+++ b/workspace.h
@@ -223,6 +223,7 @@ public:
     int activeScreen() const;
     int numScreens() const;
     void checkActiveScreen(const Client* c);
+    bool isOnCurrentHead();
     void setActiveScreenMouse(const QPoint& mousepos);
     QRect screenGeometry(int screen) const;
     int screenNumber(const QPoint& pos) const;
diff --git a/xcbutils.h b/xcbutils.h
index 9d54803974..2996273f76 100644
--- a/xcbutils.h
+++ b/xcbutils.h
@@ -178,6 +178,21 @@ public:
     }
 };
 
+inline xcb_get_input_focus_cookie_t get_input_focus(xcb_connection_t *c, xcb_window_t) {
+    return xcb_get_input_focus(c);
+}
+class CurrentInput : public Wrapper<xcb_get_input_focus_reply_t, xcb_get_input_focus_cookie_t, &xcb_get_input_focus_reply, &get_input_focus>
+{
+public:
+    CurrentInput() : Wrapper<xcb_get_input_focus_reply_t, xcb_get_input_focus_cookie_t, &xcb_get_input_focus_reply, &get_input_focus>() {}
+
+    inline xcb_window_t window() {
+        if (isNull())
+            return XCB_WINDOW_NONE;
+        return (*this)->focus;
+    }
+};
+
 class ExtensionData
 {
 public: