diff --git a/apps/openmw/mwworld/weather.hpp b/apps/openmw/mwworld/weather.hpp
index 92f2ce6a4b..a3928465c4 100644
--- a/apps/openmw/mwworld/weather.hpp
+++ b/apps/openmw/mwworld/weather.hpp
@@ -24,7 +24,6 @@ namespace ESM
 namespace MWRender
 {
     class RenderingManager;
-    enum class MoonState::Phase;
 }
 
 namespace Loading