diff --git a/CMakeLists.txt b/CMakeLists.txt
index e0dddf8fd..a4b8491a0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -85,6 +85,7 @@ ELSEIF(APPLE)
         # OSX >= 10.5 uses Cocoa windowing system, otherwise Carbon
         IF(OSG_OSX_VERSION VERSION_LESS 10.5)
             SET(OSG_WINDOWING_SYSTEM "Carbon" CACHE STRING "Windowing system type for graphics window creation; options: Carbon, Cocoa, X11 or None.")
+			SET(OSG_WINDOWING_SYSTEM_CARBON ON INTERNAL "use Carbon (apple; 32 bit only)")
         ELSE()
             SET(OSG_WINDOWING_SYSTEM "Cocoa" CACHE STRING "Windowing system type for graphics window creation; options: Carbon, Cocoa, X11 or None.")
         ENDIF()
diff --git a/include/osgViewer/GraphicsWindow b/include/osgViewer/GraphicsWindow
index b09f56e5e..c2eb6aacb 100644
--- a/include/osgViewer/GraphicsWindow
+++ b/include/osgViewer/GraphicsWindow
@@ -286,7 +286,11 @@ struct GraphicsWindowFunctionProxy
 #if defined(_WIN32)
     #define USE_GRAPHICSWINDOW()  USE_GRAPICSWINDOW_IMPLEMENTATION(Win32)
 #elif defined(__APPLE__)
+  #if defined(OSG_WINDOWING_SYSTEM_CARBON)
     #define USE_GRAPHICSWINDOW()  USE_GRAPICSWINDOW_IMPLEMENTATION(Carbon)
+  #else
+    #define USE_GRAPHICSWINDOW()  USE_GRAPICSWINDOW_IMPLEMENTATION(Cocoa)
+  #endif
 #else
     #define USE_GRAPHICSWINDOW()  USE_GRAPICSWINDOW_IMPLEMENTATION(X11)
 #endif
diff --git a/src/osg/Config.in b/src/osg/Config.in
index 583b16aa8..342069a08 100644
--- a/src/osg/Config.in
+++ b/src/osg/Config.in
@@ -36,5 +36,6 @@
 #cmakedefine OSG_PROVIDE_READFILE
 #cmakedefine OSG_USE_DEPRECATED_API
 #cmakedefine OSG_ENVVAR_SUPPORTED
+#cmakedefine OSG_WINDOWING_SYSTEM_CARBON
 
 #endif