diff --git a/src/kstyle/kstyle.cpp b/src/kstyle/kstyle.cpp
--- a/src/kstyle/kstyle.cpp
+++ b/src/kstyle/kstyle.cpp
@@ -104,7 +104,8 @@
 
 void ColorSchemeFilter::installColorScheme(QWidget *w)
 {
-    if (!w || !w->isTopLevel()) {
+    // ensure we don't call winId() on non-native widgets, bug 412675
+    if (!w || !w->isTopLevel() || !w->windowHandle()) {
         return;
     }
 #if HAVE_X11