diff --git a/kcmkwin/kwindecoration/declarative-plugin/buttonsmodel.cpp b/kcmkwin/kwindecoration/declarative-plugin/buttonsmodel.cpp
--- a/kcmkwin/kwindecoration/declarative-plugin/buttonsmodel.cpp
+++ b/kcmkwin/kwindecoration/declarative-plugin/buttonsmodel.cpp
@@ -163,8 +163,18 @@
     if (sourceIndex == qMax(0, targetIndex)) {
         return;
     }
-    beginMoveRows(QModelIndex(), sourceIndex, sourceIndex, QModelIndex(), targetIndex + 1);
-    m_buttons.insert(qMax(0, targetIndex), m_buttons.takeAt(sourceIndex));
+
+    /* When moving an item down, the destination index needs to be incremented
+       by one, as explained in the documentation:
+       http://doc.qt.nokia.com/qabstractitemmodel.html#beginMoveRows */
+    if (targetIndex > sourceIndex) {
+        // Row will be moved down
+        beginMoveRows(QModelIndex(), sourceIndex, sourceIndex, QModelIndex(), targetIndex + 1);
+    } else {
+        beginMoveRows(QModelIndex(), sourceIndex, sourceIndex, QModelIndex(), qMax(0, targetIndex));
+    }
+
+    m_buttons.move(sourceIndex, qMax(0, targetIndex));
     endMoveRows();
 }