diff --git a/library/modules/MapCache.cpp b/library/modules/MapCache.cpp
index 404626e00..2ebfd9644 100644
--- a/library/modules/MapCache.cpp
+++ b/library/modules/MapCache.cpp
@@ -74,7 +74,9 @@ using df::global::world;
 
 extern bool GetLocalFeature(t_feature &feature, df::coord2d rgn_pos, int32_t index);
 
+#ifdef LINUX_BUILD
 const unsigned MapExtras::BiomeInfo::MAX_LAYERS;
+#endif
 
 const BiomeInfo MapCache::biome_stub = {
     df::coord2d(),