diff --git a/components/stereo/frustum.hpp b/components/stereo/frustum.hpp
index 35e3adf95a..cf619529b4 100644
--- a/components/stereo/frustum.hpp
+++ b/components/stereo/frustum.hpp
@@ -24,7 +24,7 @@ namespace osgViewer
     class Viewer;
 }
 
-namespace usgUtil
+namespace osgUtil
 {
     class CullVisitor;
 }