diff --git a/src/osgPlugins/osc/CMakeLists.txt b/src/osgPlugins/osc/CMakeLists.txt
index 75bb17f54..468c20df8 100755
--- a/src/osgPlugins/osc/CMakeLists.txt
+++ b/src/osgPlugins/osc/CMakeLists.txt
@@ -44,6 +44,8 @@ ELSE()
     )
 ENDIF()
 
+INCLUDE_DIRECTORIES(${OpenSceneGraph_SOURCE_DIR}/src/osgPlugins/osc)
+
 SET(TARGET_ADDED_LIBRARIES osgGA )
 
 #### end var setup  ###