diff --git a/FL/porting.H b/FL/porting.H
index 776dd8779..01984aa71 100644
--- a/FL/porting.H
+++ b/FL/porting.H
@@ -25,6 +25,8 @@
 #endif // !Fl_X_H
 
 
+typedef void *Window;
+
 #if !(defined(FL_LIBRARY) || defined(FL_INTERNALS)) // this part is used when compiling an application program
 #  include <FL/Fl_Widget.H>
 
@@ -43,8 +45,6 @@ typedef void *Fl_Offscreen;
 struct XPoint { int x, y; };
 struct XRectangle {int x, y, width, height;};
 
-typedef void *Window;
-
 //typedef float CGFloat;
 
 inline Fl_Region XRectangleRegion(int x, int y, int w, int h) {
diff --git a/src/drivers/PicoSDL/Fl_PicoSDL_Screen_Driver.cxx b/src/drivers/PicoSDL/Fl_PicoSDL_Screen_Driver.cxx
index a4a44a748..2c450915e 100644
--- a/src/drivers/PicoSDL/Fl_PicoSDL_Screen_Driver.cxx
+++ b/src/drivers/PicoSDL/Fl_PicoSDL_Screen_Driver.cxx
@@ -156,6 +156,22 @@ Window fl_window;
 //void Fl_Image_Surface::translate(int x, int y) { }
 //void Fl_Image_Surface::untranslate() { }
 
+void Fl::add_fd(int, void (*)(int, void*), void*)
+{
+}
+
+void Fl::remove_fd(int)
+{
+}
+
+int Fl_Window::decorated_h()
+{
+}
+
+int Fl_Window::decorated_w()
+{
+}
+
 /*
  #define __APPLE__
  #include <SDL2/SDL.h>