diff --git a/apps/openmw/mwworld/weather.cpp b/apps/openmw/mwworld/weather.cpp
index 89c5892a9f..2d63dd6d55 100644
--- a/apps/openmw/mwworld/weather.cpp
+++ b/apps/openmw/mwworld/weather.cpp
@@ -579,7 +579,7 @@ void WeatherManager::stopSounds(bool stopAll)
     }
 }
 
-Weather::Type WeatherManager::nextWeather(const ESM::Region* region)
+Weather::Type WeatherManager::nextWeather(const ESM::Region* region) const
 {
     /*
      * All probabilities must add to 100 (responsibility of the user).
diff --git a/apps/openmw/mwworld/weather.hpp b/apps/openmw/mwworld/weather.hpp
index fa305dc3c6..90b0a2dc5e 100644
--- a/apps/openmw/mwworld/weather.hpp
+++ b/apps/openmw/mwworld/weather.hpp
@@ -202,7 +202,7 @@ namespace MWWorld
         float calculateAngleFade (const std::string& moonName, float angle) const;
 
         void setWeather(Weather::Type weatherType, bool instant=false);
-        Weather::Type nextWeather(const ESM::Region* region);
+        Weather::Type nextWeather(const ESM::Region* region) const;
         WeatherResult mResult;
         float mSunriseTime;
         float mSunsetTime;