diff --git a/Graphics/drawContext.h b/Graphics/drawContext.h
index 8322755e0584ebd1cc480ac3ab940a2aa85405e6..2d7295c145ccad6d7dfa29c63e09df8029df27c8 100644
--- a/Graphics/drawContext.h
+++ b/Graphics/drawContext.h
@@ -76,6 +76,8 @@ class drawTransformScaled : public drawTransform {
 // widget toolkit (FLTK, Qt, etc.)
 class drawContextGlobal {
  public:
+  drawContextGlobal(){}
+  virtual ~drawContextGlobal(){}
   virtual void draw(){}
   virtual void drawCurrentOpenglWindow(bool make_current){}
   virtual int getFontIndex(const char *fontname){ return 0; }