diff --git a/src/osgViewer/GraphicsWindowX11.cpp b/src/osgViewer/GraphicsWindowX11.cpp
index 358357aa5..5d74cd782 100644
--- a/src/osgViewer/GraphicsWindowX11.cpp
+++ b/src/osgViewer/GraphicsWindowX11.cpp
@@ -27,7 +27,6 @@
 #include <X11/Xmd.h>
 #include <X11/keysym.h>
 #include <X11/cursorfont.h>
-#include <X11/Intrinsic.h>
 
 #include <X11/Xmd.h>        /* For CARD16 */