diff --git a/vncviewer/Viewport.h b/vncviewer/Viewport.h
index ac1ec33..0967fcb 100644
--- a/vncviewer/Viewport.h
+++ b/vncviewer/Viewport.h
@@ -29,6 +29,7 @@
 
 class CConn;
 class PlatformPixelBuffer;
+class Surface;
 
 class Viewport : public Fl_Widget {
 public:
@@ -46,6 +47,8 @@
   void setCursor(int width, int height, const rfb::Point& hotspot,
                  void* data, void* mask);
 
+  void draw(Surface* dst);
+
   // Fl_Widget callback methods
 
   void draw();