diff --git a/src/Main/fg_os_osgviewer.cxx b/src/Main/fg_os_osgviewer.cxx
index b58d60664..a241e60c3 100644
--- a/src/Main/fg_os_osgviewer.cxx
+++ b/src/Main/fg_os_osgviewer.cxx
@@ -45,7 +45,6 @@
 #include <osg/View>
 #include <osgViewer/ViewerEventHandlers>
 #include <osgViewer/Viewer>
-#include <osgGA/MatrixManipulator>
 
 #include <Include/general.hxx>
 #include <Scenery/scenery.hxx>