diff --git a/apps/openmw/mwworld/weather.cpp b/apps/openmw/mwworld/weather.cpp
index 7a36d6ac7..4440ed030 100644
--- a/apps/openmw/mwworld/weather.cpp
+++ b/apps/openmw/mwworld/weather.cpp
@@ -1,7 +1,8 @@
-#include "weather.hpp"
-
+#define _USE_MATH_DEFINES
 #include <cmath>
 
+#include "weather.hpp"
+
 #include <components/esm/weatherstate.hpp>
 
 #include "../mwbase/environment.hpp"