diff --git a/simgear/scene/viewer/ClusteredForward.cxx b/simgear/scene/viewer/ClusteredForward.cxx
index e2b50180..6e5f4098 100644
--- a/simgear/scene/viewer/ClusteredForward.cxx
+++ b/simgear/scene/viewer/ClusteredForward.cxx
@@ -21,6 +21,7 @@
 #include <osg/RenderInfo>
 #include <osg/Texture3D>
 #include <osg/TextureBuffer>
+#include <osg/Version>
 
 namespace simgear {
 namespace compositor {