diff --git a/vncviewer/OptionsDialog.cxx b/vncviewer/OptionsDialog.cxx
index df9f355..e21f2dd 100644
--- a/vncviewer/OptionsDialog.cxx
+++ b/vncviewer/OptionsDialog.cxx
@@ -41,7 +41,11 @@
 
 #include <FL/Fl_Tabs.H>
 #include <FL/Fl_Button.H>
+#include <FL/Fl_Check_Button.H>
 #include <FL/Fl_Return_Button.H>
+#include <FL/Fl_Round_Button.H>
+#include <FL/Fl_Int_Input.H>
+#include <FL/Fl_Choice.H>
 
 using namespace std;
 using namespace rdr;
diff --git a/vncviewer/OptionsDialog.h b/vncviewer/OptionsDialog.h
index b3ac015..a6b504e 100644
--- a/vncviewer/OptionsDialog.h
+++ b/vncviewer/OptionsDialog.h
@@ -22,11 +22,14 @@
 #include <map>
 
 #include <FL/Fl_Window.H>
-#include <FL/Fl_Group.H>
-#include <FL/Fl_Check_Button.H>
-#include <FL/Fl_Round_Button.H>
-#include <FL/Fl_Int_Input.H>
-#include <FL/Fl_Choice.H>
+
+class Fl_Widget;
+class Fl_Group;
+class Fl_Check_Button;
+class Fl_Round_Button;
+class Fl_Input;
+class Fl_Int_Input;
+class Fl_Choice;
 
 typedef void (OptionsCallback)(void*);
 
diff --git a/vncviewer/ServerDialog.h b/vncviewer/ServerDialog.h
index e023659..7926849 100644
--- a/vncviewer/ServerDialog.h
+++ b/vncviewer/ServerDialog.h
@@ -20,8 +20,9 @@
 #define __SERVERDIALOG_H__
 
 #include <FL/Fl_Window.H>
-#include <FL/Fl_Input.H>
-#include <FL/Fl_File_Chooser.H>
+
+class Fl_Widget;
+class Fl_Input;
 
 class ServerDialog : public Fl_Window {
 protected:
diff --git a/vncviewer/Viewport.cxx b/vncviewer/Viewport.cxx
index 733e4a2..d784a42 100644
--- a/vncviewer/Viewport.cxx
+++ b/vncviewer/Viewport.cxx
@@ -52,6 +52,9 @@
 #include <FL/fl_draw.H>
 #include <FL/fl_ask.H>
 
+#include <FL/Fl_Menu.H>
+#include <FL/Fl_Menu_Button.H>
+
 #ifdef WIN32
 #include "win32.h"
 #endif
diff --git a/vncviewer/Viewport.h b/vncviewer/Viewport.h
index c66c19a..0410fb8 100644
--- a/vncviewer/Viewport.h
+++ b/vncviewer/Viewport.h
@@ -24,13 +24,8 @@
 
 #include <FL/Fl.H>
 #include <FL/Fl_Widget.H>
-#include <FL/Fl_Menu_Button.H>
-#include <FL/Fl_RGB_Image.H>
 
-#include <rfb/Rect.h>
 #include <rfb/Region.h>
-#include <rfb/Timer.h>
-#include <rfb/PixelBuffer.h>
 #include <rfb/PixelTransformer.h>
 
 #if defined(WIN32)
@@ -46,6 +41,9 @@
 // #include "PlatformPixelBuffer.h"
 //
 
+class Fl_Menu_Button;
+class Fl_RGB_Image;
+
 class CConn;
 
 class Viewport : public Fl_Widget {
diff --git a/vncviewer/Win32PixelBuffer.h b/vncviewer/Win32PixelBuffer.h
index ae2b71a..7d91e09 100644
--- a/vncviewer/Win32PixelBuffer.h
+++ b/vncviewer/Win32PixelBuffer.h
@@ -19,6 +19,8 @@
 #ifndef __WIN32PIXELBUFFER_H__
 #define __WIN32PIXELBUFFER_H__
 
+#include <windows.h>
+
 #include <rfb/PixelBuffer.h>
 
 class PlatformPixelBuffer: public rfb::FullFramePixelBuffer {