diff --git a/FL/Fl_Tree_Item.H b/FL/Fl_Tree_Item.H
index b76395334..cddc40e3f 100644
--- a/FL/Fl_Tree_Item.H
+++ b/FL/Fl_Tree_Item.H
@@ -93,8 +93,13 @@ protected:
   void _Init(const Fl_Tree_Prefs &prefs, Fl_Tree *tree);
   void show_widgets();
   void hide_widgets();
+#if FL_ABI_VERSION >= 10403
+  virtual void draw_vertical_connector(int x, int y1, int y2, const Fl_Tree_Prefs &prefs);
+  virtual void draw_horizontal_connector(int x1, int x2, int y, const Fl_Tree_Prefs &prefs);
+#else
   void draw_vertical_connector(int x, int y1, int y2, const Fl_Tree_Prefs &prefs);
   void draw_horizontal_connector(int x1, int x2, int y, const Fl_Tree_Prefs &prefs);
+#endif
   void recalc_tree();
   int calc_item_height(const Fl_Tree_Prefs &prefs) const;
   Fl_Color drawfgcolor() const;
diff --git a/src/Fl_Tree_Item.cxx b/src/Fl_Tree_Item.cxx
index 616a77392..5234bbd3c 100644
--- a/src/Fl_Tree_Item.cxx
+++ b/src/Fl_Tree_Item.cxx
@@ -705,7 +705,8 @@ int Fl_Tree_Item::swap_children(Fl_Tree_Item *a, Fl_Tree_Item *b) {
   return(0);
 }
 
-/// Internal: Horizontal connector line based on preference settings.
+/// Horizontal connector line based on preference settings.
+/// This method can be overridden to implement custom connection line drawing.
 /// \param[in] x1 The left hand X position of the horizontal connector
 /// \param[in] x2 The right hand X position of the horizontal connector
 /// \param[in] y  The vertical position of the horizontal connector
@@ -730,7 +731,8 @@ void Fl_Tree_Item::draw_horizontal_connector(int x1, int x2, int y, const Fl_Tre
   }
 }
 
-/// Internal: Vertical connector line based on preference settings.
+/// Vertical connector line based on preference settings.
+/// This method can be overridden to implement custom connection line drawing.
 /// \param[in] x     The x position of the vertical connector
 /// \param[in] y1    The top of the vertical connector
 /// \param[in] y2    The bottom of the vertical connector