diff --git a/layers.cpp b/layers.cpp
index ed12b52232..b8c3aca127 100644
--- a/layers.cpp
+++ b/layers.cpp
@@ -723,13 +723,11 @@ QList<Toplevel *> Workspace::xStackingOrder() const
 
 void Workspace::updateXStackingOrder()
 {
-    x_stacking.clear();
-    std::unique_ptr<Xcb::Tree> tree{std::move(m_xStackingQueryTree)};
     // use our own stacking order, not the X one, as they may differ
-    foreach (Toplevel * c, stacking_order)
-    x_stacking.append(c);
+    x_stacking = stacking_order;
 
-    if (tree && !tree->isNull()) {
+    if (m_xStackingQueryTree && !m_xStackingQueryTree->isNull()) {
+        std::unique_ptr<Xcb::Tree> tree{std::move(m_xStackingQueryTree)};
         xcb_window_t *windows = tree->children();
         const auto count = tree->data()->children_len;
         int foundUnmanagedCount = unmanaged.count();