diff --git a/apps/openmw/mwworld/weather.hpp b/apps/openmw/mwworld/weather.hpp
index 93cfed68b..4290b21aa 100644
--- a/apps/openmw/mwworld/weather.hpp
+++ b/apps/openmw/mwworld/weather.hpp
@@ -19,7 +19,7 @@ namespace ESM
 namespace MWRender
 {
     class RenderingManager;
-    class MoonState;
+    struct MoonState;
 }
 
 namespace Loading