diff --git a/src/osgViewer/GraphicsWindowCarbon.cpp b/src/osgViewer/GraphicsWindowCarbon.cpp
index 65b0ff164..0fbb6f21c 100644
--- a/src/osgViewer/GraphicsWindowCarbon.cpp
+++ b/src/osgViewer/GraphicsWindowCarbon.cpp
@@ -1097,22 +1097,6 @@ public:
 
 };
 
-
-}
-
-#if 1
 REGISTER_WINDOWINGSYSTEMINTERFACE(Carbon, CarbonWindowingSystemInterface)
-#else
 
-#ifdef USE_DARWIN_CARBON_IMPLEMENTATION
-RegisterWindowingSystemInterfaceProxy<CarbonWindowingSystemInterface> createWindowingSystemInterfaceProxy;
-#endif
-
-// declare C entry point for static compilation.
-extern "C" void graphicswindow_Carbon(void)
-{
-    osg::GraphicsContext::setWindowingSystemInterface(new osgViewer::CarbonWindowingSystemInterface());
 }
-#endif
-
-#endif
diff --git a/src/osgViewer/GraphicsWindowCocoa.mm b/src/osgViewer/GraphicsWindowCocoa.mm
index e2afd5173..72220d16b 100644
--- a/src/osgViewer/GraphicsWindowCocoa.mm
+++ b/src/osgViewer/GraphicsWindowCocoa.mm
@@ -1827,18 +1827,6 @@ private:
 
 };
 
-}
-
-#if 1
 REGISTER_WINDOWINGSYSTEMINTERFACE(Cocoa, CocoaWindowingSystemInterface)
-#else
-#ifdef USE_DARWIN_COCOA_IMPLEMENTATION
-RegisterWindowingSystemInterfaceProxy<osgViewer::CocoaWindowingSystemInterface> createWindowingSystemInterfaceProxy;
-#endif
 
-// declare C entry point for static compilation.
-extern "C" void graphicswindow_Cocoa(void)
-{
-    osg::GraphicsContext::setWindowingSystemInterface(new osgViewer::CocoaWindowingSystemInterface());
 }
-#endif
diff --git a/src/osgViewer/GraphicsWindowIOS.mm b/src/osgViewer/GraphicsWindowIOS.mm
index 0c647e5ba..94444af25 100644
--- a/src/osgViewer/GraphicsWindowIOS.mm
+++ b/src/osgViewer/GraphicsWindowIOS.mm
@@ -1224,17 +1224,6 @@ public:
     }
 };
 
-}//end namspace
-
-#if 1
 REGISTER_WINDOWINGSYSTEMINTERFACE(IOS, ConcreteIOSWindowingSystemInterface)
-#else
-RegisterWindowingSystemInterfaceProxy<osgViewer::ConcreteIOSWindowingSystemInterface> createWindowingSystemInterfaceProxy;
 
-
-// declare C entry point for static compilation.
-extern "C" void graphicswindow_IOS(void)
-{
-    osg::GraphicsContext::setWindowingSystemInterface(new osgViewer::ConcreteIOSWindowingSystemInterface());
-}
-#endif
+}//end namspace