diff --git a/kwin/main.js.in b/kwin/main.js.in
index b2cec57..b4c7475 100755
--- a/kwin/main.js.in
+++ b/kwin/main.js.in
@@ -80,6 +80,10 @@ class %EFFECT_CLASS% {
             return window.hasDecoration;
         }
 
+        if (!window.hasDecoration && window.onAllDesktops) {
+            return false
+        }
+
         if (blacklist.indexOf(window.windowClass) != -1) {
             return false;
         }