diff --git a/CMakeLists.txt b/CMakeLists.txt
index d3c6c9408..94ddaaa0e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -31,7 +31,7 @@ PROJECT(OpenSceneGraph)
 SET(OPENSCENEGRAPH_MAJOR_VERSION 2)
 SET(OPENSCENEGRAPH_MINOR_VERSION 9)
 SET(OPENSCENEGRAPH_PATCH_VERSION 8)
-SET(OPENSCENEGRAPH_SOVERSION 64)
+SET(OPENSCENEGRAPH_SOVERSION 66)
 
 # set to 0 when not a release candidate, non zero means that any generated 
 # svn tags will be treated as release candidates of given number