diff --git a/effects/fadedesktop/package/contents/code/main.js b/effects/fadedesktop/package/contents/code/main.js
--- a/effects/fadedesktop/package/contents/code/main.js
+++ b/effects/fadedesktop/package/contents/code/main.js
@@ -40,16 +40,23 @@
             continue;
         }
 
-        if (w.desktop != oldDesktop && w.desktop != newDesktop) {
+        // If the window is not on the old and the new desktop or it's
+        // on both of them, then don't animate it.
+        var onOldDesktop = w.isOnDesktop(oldDesktop);
+        var onNewDesktop = w.isOnDesktop(newDesktop);
+        if (onOldDesktop == onNewDesktop) {
             continue;
         }
+
         if (w.minimized) {
             continue;
         }
+
         if (!w.isOnActivity(effects.currentActivity)){
             continue;
         }
-        if (w.desktop == oldDesktop) {
+
+        if (onOldDesktop) {
             animate({
                 window: w,
                 duration: duration,
diff --git a/libkwineffects/kwineffects.h b/libkwineffects/kwineffects.h
--- a/libkwineffects/kwineffects.h
+++ b/libkwineffects/kwineffects.h
@@ -2044,7 +2044,7 @@
     bool isOnAllActivities() const;
     QStringList activities() const;
 
-    bool isOnDesktop(int d) const;
+    Q_SCRIPTABLE bool isOnDesktop(int d) const;
     bool isOnCurrentDesktop() const;
     bool isOnAllDesktops() const;
     int desktop() const; // prefer isOnXXX()