diff --git a/src/osg/CMakeLists.txt b/src/osg/CMakeLists.txt
index 57b155ef1..c965e9f97 100644
--- a/src/osg/CMakeLists.txt
+++ b/src/osg/CMakeLists.txt
@@ -294,6 +294,6 @@ TARGET_LINK_LIBRARIES(${LIB_NAME}
 )
 
 # This file should not be built, but should be in the project file
-LIST(APPEND LIB_PUBLIC_HEADERS Matrix_implementation.cpp)
+# LIST(APPEND LIB_PUBLIC_HEADERS Matrix_implementation.cpp)
 
 INCLUDE(ModuleInstall OPTIONAL)