diff --git a/src/H5Format.cpp b/src/H5Format.cpp
index 5362303..660ffc1 100644
--- a/src/H5Format.cpp
+++ b/src/H5Format.cpp
@@ -280,7 +280,11 @@ void H5FormatUtils::write_attribute(H5::H5Object& target, const h5_attr& attribu
 
 void H5FormatUtils::write_format_data(H5::Group& file_node, const h5_parent& format_node, const std::map<std::string, h5_value>& values) 
 {
-    auto node_group = H5FormatUtils::create_group(file_node, format_node.name);
+    H5::Group node_group = file_node;
+
+    if (format_node.node_type == GROUP) {
+        node_group = H5FormatUtils::create_group(file_node, format_node.name);
+    }
 
     for (const auto item_ptr : format_node.items) {
         const h5_base& item = *item_ptr;
diff --git a/src/H5Format.hpp b/src/H5Format.hpp
index 9212b50..e803aeb 100644
--- a/src/H5Format.hpp
+++ b/src/H5Format.hpp
@@ -13,6 +13,7 @@ typedef boost::any h5_value;
 
 enum NODE_TYPE 
 {
+    EMPTY_ROOT,
     ATTRIBUTE,
     DATASET,
     GROUP
@@ -63,7 +64,7 @@ struct h5_parent: public h5_base
 
 struct h5_group : public h5_parent 
 {
-    h5_group(const std::string& name, const std::list<std::shared_ptr<h5_base>>& items) : 
+    h5_group(const std::string& name, const std::list<std::shared_ptr<h5_base>>& items={}) : 
         h5_parent(name, GROUP, items) {};
 };