diff --git a/show_struct.py b/show_struct.py
index 701d1af..3661788 100755
--- a/show_struct.py
+++ b/show_struct.py
@@ -42,7 +42,7 @@ def outline(self, data):
         for path in sorted(self.paths):
             ret.append({
                 'path': path,
-                'values': sorted(self.values_for_path[path].keys())
+                'values': sorted(self.values_for_path[path].keys(), key=lambda x: x is not None)
             })
         return ret