diff --git a/src/osgPlugins/lwo/old_Lwo2.cpp b/src/osgPlugins/lwo/old_Lwo2.cpp
index 35cd02e14..cf7b49f12 100644
--- a/src/osgPlugins/lwo/old_Lwo2.cpp
+++ b/src/osgPlugins/lwo/old_Lwo2.cpp
@@ -30,6 +30,7 @@
 #include <osg/Material>
 #include <osg/CullFace>
 #include <osg/BlendFunc>
+#include <osg/io_utils>
 
 #include <osgDB/Registry>
 #include <osgDB/ReadFile>
diff --git a/src/osgPlugins/lwo/old_Lwo2Layer.cpp b/src/osgPlugins/lwo/old_Lwo2Layer.cpp
index b6fd8308d..1a672bc44 100644
--- a/src/osgPlugins/lwo/old_Lwo2Layer.cpp
+++ b/src/osgPlugins/lwo/old_Lwo2Layer.cpp
@@ -24,6 +24,7 @@
  */
 
 #include "old_Lwo2Layer.h"
+#include <osg/io_utils>
 
 Lwo2Layer::Lwo2Layer():
   _number(0),