diff --git a/include/osg/BufferObject b/include/osg/BufferObject
index 5825c9fd6..878963fb3 100644
--- a/include/osg/BufferObject
+++ b/include/osg/BufferObject
@@ -35,8 +35,6 @@
 
     #define GL_ARRAY_BUFFER_ARB               0x8892
     #define GL_ELEMENT_ARRAY_BUFFER_ARB       0x8893
-    #define GL_PIXEL_PACK_BUFFER_ARB          0x88EB
-    #define GL_PIXEL_UNPACK_BUFFER_ARB        0x88EC
     #define GL_ARRAY_BUFFER_BINDING_ARB       0x8894
     #define GL_ELEMENT_ARRAY_BUFFER_BINDING_ARB 0x8895
     #define GL_VERTEX_ARRAY_BUFFER_BINDING_ARB 0x8896
@@ -49,8 +47,6 @@
     #define GL_FOG_COORDINATE_ARRAY_BUFFER_BINDING_ARB 0x889D
     #define GL_WEIGHT_ARRAY_BUFFER_BINDING_ARB 0x889E
     #define GL_VERTEX_ATTRIB_ARRAY_BUFFER_BINDING_ARB 0x889F
-    #define GL_PIXEL_PACK_BUFFER_BINDING_ARB    0x88ED
-    #define GL_PIXEL_UNPACK_BUFFER_BINDING_ARB  0x88EF
     #define GL_STREAM_DRAW_ARB                0x88E0
     #define GL_STREAM_READ_ARB                0x88E1
     #define GL_STREAM_COPY_ARB                0x88E2
@@ -71,6 +67,13 @@
 
 #endif
 
+#ifndef GL_ARB_pixel_buffer_object
+    #define GL_PIXEL_PACK_BUFFER_ARB          0x88EB
+    #define GL_PIXEL_UNPACK_BUFFER_ARB        0x88EC
+    #define GL_PIXEL_PACK_BUFFER_BINDING_ARB    0x88ED
+    #define GL_PIXEL_UNPACK_BUFFER_BINDING_ARB  0x88EF
+#endif
+
 namespace osg 
 {