diff --git a/libtaskmanager/waylandtasksmodel.cpp b/libtaskmanager/waylandtasksmodel.cpp
--- a/libtaskmanager/waylandtasksmodel.cpp
+++ b/libtaskmanager/waylandtasksmodel.cpp
@@ -465,6 +465,8 @@
         // FIXME Implement.
     } else if (role == AppPid) {
         return window->pid();
+    } else if (role == StackingOrder) {
+        return d->windowManagement->stackingOrder().indexOf(window->internalId());
     } else if (role == ApplicationMenuObjectPath) {
         return window->applicationMenuObjectPath();
     } else if (role == ApplicationMenuServiceName) {