diff --git a/test/fullscreen.cxx b/test/fullscreen.cxx
index 1d68df7f0..23de9e76d 100644
--- a/test/fullscreen.cxx
+++ b/test/fullscreen.cxx
@@ -99,7 +99,7 @@ void shape_window::draw() {
 #include <FL/fl_draw.H>
 
 class shape_window : public Fl_Window {
-  void draw();
+  void draw() FL_OVERRIDE;
 public:
   int sides;
   shape_window(int x,int y,int w,int h,const char *l=0);