1 files changed, 4 insertions, 0 deletions
diff --git a/sigmodr/tree/TreeModel.cpp b/sigmodr/tree/TreeModel.cpp
index 15f8dae2..82dd7ec8 100644
--- a/sigmodr/tree/TreeModel.cpp
+++ b/sigmodr/tree/TreeModel.cpp
@@ -50,7 +50,11 @@ QVariant TreeModel::data(const QModelIndex& index, const int role) const
 QModelIndex TreeModel::index(const int row, const int column, const QModelIndex& parent) const
 {
     if (!parent.isValid())
+    {
+        if ((row == -1) || (column == -1))
+            return createIndex(0, 0, m_root);
         return QModelIndex();
+    }
     TreeItem* item = static_cast<TreeItem*>(parent.internalPointer());
     if (column || (row < 0) || (item->childCount() <= row))
         return QModelIndex();