diff --git a/effects/fallapart/fallapart.cpp b/effects/fallapart/fallapart.cpp
index d2dea06f75..20d44f8d58 100644
--- a/effects/fallapart/fallapart.cpp
+++ b/effects/fallapart/fallapart.cpp
@@ -146,6 +146,12 @@ bool FallApartEffect::isRealWindow(EffectWindow* w)
     qCDebug(KWINEFFECTS) << "Splash:" << w->isSplash();
     qCDebug(KWINEFFECTS) << "Normal:" << w->isNormalWindow();
     */
+    if (w->isPopupWindow()) {
+        return false;
+    }
+    if (w->isX11Client() && !w->isManaged()) {
+        return false;
+    }
     if (!w->isNormalWindow())
         return false;
     return true;
diff --git a/main_x11.cpp b/main_x11.cpp
index e5e4d2b690..c83b8240b9 100644
--- a/main_x11.cpp
+++ b/main_x11.cpp
@@ -408,6 +408,7 @@ KWIN_EXPORT int kdemain(int argc, char * argv[])
     setenv("QT_QPA_PLATFORM", "xcb", true);
 
     qunsetenv("QT_DEVICE_PIXEL_RATIO");
+    qunsetenv("QT_SCALE_FACTOR");
     QCoreApplication::setAttribute(Qt::AA_DisableHighDpiScaling);
 
     KWin::ApplicationX11 a(argc, argv);