diff --git a/include/osgUtil/Optimizer b/include/osgUtil/Optimizer
index 8ee3b5e35..11f4da648 100644
--- a/include/osgUtil/Optimizer
+++ b/include/osgUtil/Optimizer
@@ -67,23 +67,23 @@ class OSGUTIL_EXPORT Optimizer
 
         enum OptimizationOptions
         {
-            FLATTEN_STATIC_TRANSFORMS = 0x001,
-            REMOVE_REDUNDANT_NODES =    0x002,
-            REMOVE_LOADED_PROXY_NODES = 0x004,
-            COMBINE_ADJACENT_LODS =     0x008,
-            SHARE_DUPLICATE_STATE =     0x010,
-            MERGE_GEOMETRY =            0x020,
-            CHECK_GEOMETRY =            0x040,
-            SPATIALIZE_GROUPS =         0x080,
-            COPY_SHARED_NODES =         0x100,
-            TRISTRIP_GEOMETRY =         0x200,
-            TESSELLATE_GEOMETRY =       0x400,
-            OPTIMIZE_TEXTURE_SETTINGS = 0x800,
-            MERGE_GEODES =              0x1000,
-            FLATTEN_BILLBOARDS =        0x2000,
-            TEXTURE_ATLAS_BUILDER =     0x4000,
-            STATIC_OBJECT_DETECTION =   0x8000,
-            FLATTEN_STATIC_TRANSFORMS_DUPLICATING_SHARED_SUBGRAPHS = 0x100,
+            FLATTEN_STATIC_TRANSFORMS = (1 << 0),
+            REMOVE_REDUNDANT_NODES =    (1 << 1),
+            REMOVE_LOADED_PROXY_NODES = (1 << 2),
+            COMBINE_ADJACENT_LODS =     (1 << 3),
+            SHARE_DUPLICATE_STATE =     (1 << 4),
+            MERGE_GEOMETRY =            (1 << 5),
+            CHECK_GEOMETRY =            (1 << 6),
+            SPATIALIZE_GROUPS =         (1 << 7),
+            COPY_SHARED_NODES =         (1 << 8),
+            TRISTRIP_GEOMETRY =         (1 << 9),
+            TESSELLATE_GEOMETRY =       (1 << 10),
+            OPTIMIZE_TEXTURE_SETTINGS = (1 << 11),
+            MERGE_GEODES =              (1 << 12),
+            FLATTEN_BILLBOARDS =        (1 << 13),
+            TEXTURE_ATLAS_BUILDER =     (1 << 14),
+            STATIC_OBJECT_DETECTION =   (1 << 15),
+            FLATTEN_STATIC_TRANSFORMS_DUPLICATING_SHARED_SUBGRAPHS = (1 << 16),
             DEFAULT_OPTIMIZATIONS = FLATTEN_STATIC_TRANSFORMS |
                                 REMOVE_REDUNDANT_NODES |
                                 REMOVE_LOADED_PROXY_NODES |