diff --git a/demo/treelayout.h b/demo/treelayout.h
index e72ef0e..498210c 100644
--- a/demo/treelayout.h
+++ b/demo/treelayout.h
@@ -26,7 +26,7 @@
 {
 public:
   OneLevelTreeLayout(){}
-  virtual void setOneLevelLayout(std::vector<Coordinate> &v, int childNumber);
+  virtual void setOneLevelLayout(std::vector<Coordinate> &childNodesCo);
   virtual ~OneLevelTreeLayout(){}
 };
 #endif