diff --git a/applets/taskmanager/package/contents/code/tools.js b/applets/taskmanager/package/contents/code/tools.js
--- a/applets/taskmanager/package/contents/code/tools.js
+++ b/applets/taskmanager/package/contents/code/tools.js
@@ -161,9 +161,5 @@
     default:
         effectivePrefix = "south-" + prefix;
     }
-    if (!frame.hasElementPrefix(effectivePrefix)) {
-        return prefix;
-    }
-    return effectivePrefix;
-
+    return [effectivePrefix, prefix];
 }
diff --git a/applets/taskmanager/package/contents/ui/Task.qml b/applets/taskmanager/package/contents/ui/Task.qml
--- a/applets/taskmanager/package/contents/ui/Task.qml
+++ b/applets/taskmanager/package/contents/ui/Task.qml
@@ -289,14 +289,6 @@
         imagePath: "widgets/tasks"
         property string basePrefix: "normal"
         prefix: TaskTools.taskPrefix(basePrefix)
-        onRepaintNeeded: updatePrefix()
-
-        function updatePrefix() {
-            prefix = Qt.binding(function() {
-                return TaskTools.taskPrefix(basePrefix);
-            });
-        }
-
 
         PlasmaCore.ToolTipArea {
             id: toolTipArea
diff --git a/applets/taskmanager/package/contents/ui/TaskProgressOverlay.qml b/applets/taskmanager/package/contents/ui/TaskProgressOverlay.qml
--- a/applets/taskmanager/package/contents/ui/TaskProgressOverlay.qml
+++ b/applets/taskmanager/package/contents/ui/TaskProgressOverlay.qml
@@ -43,16 +43,7 @@
             height: background.height
 
             imagePath: "widgets/tasks"
-            prefix: calculatePrefix()
-            onRepaintNeeded: prefix = calculatePrefix()
-
-            function calculatePrefix() {
-                var prefix = TaskTools.taskPrefix("progress")
-                if (!frame.hasElementPrefix(prefix)) {
-                    prefix = TaskTools.taskPrefix("hover")
-                }
-                return prefix
-            }
+            prefix: TaskTools.taskPrefix("progress").concat(TaskTools.taskPrefix("hover"))
         }
     }
 }
diff --git a/desktoppackage/contents/views/Panel.qml b/desktoppackage/contents/views/Panel.qml
--- a/desktoppackage/contents/views/Panel.qml
+++ b/desktoppackage/contents/views/Panel.qml
@@ -25,7 +25,6 @@
     id: root
 
     imagePath: containment && containment.backgroundHints === PlasmaCore.Types.NoBackground ? "" : "widgets/panel-background"
-    onRepaintNeeded: adjustPrefix();
 
     enabledBorders: panel.enabledBorders
 
@@ -53,12 +52,9 @@
             break;
         default:
             prefix = "";
+            return;
         }
-        if (hasElementPrefix(pre)) {
-            prefix = pre;
-        } else {
-            prefix = "";
-        }
+        prefix = [prefix, ""];
     }
 
     onContainmentChanged: {