diff --git a/include/wx/unix/glx11.h b/include/wx/unix/glx11.h
index 687982e068..9f8d6353e2 100644
--- a/include/wx/unix/glx11.h
+++ b/include/wx/unix/glx11.h
@@ -132,7 +132,7 @@ private:
 class WXDLLIMPEXP_GL wxGLApp : public wxGLAppBase
 {
 public:
-    wxGLApp();
+    wxGLApp() : wxGLAppBase() { }
 
     // implement wxGLAppBase method
     virtual bool InitGLVisual(const int *attribList)