Index: simgear/scene/viewer/Compositor.hxx
--- simgear/scene/viewer/Compositor.hxx.orig
+++ simgear/scene/viewer/Compositor.hxx
@@ -3,6 +3,7 @@
 
 #pragma once
 
+#include <array>
 #include <unordered_map>
 #include <vector>
 #include <array>
