diff --git a/lib/rmg/CMapGenerator.cpp b/lib/rmg/CMapGenerator.cpp
index 0c7f6c963..0c3c3eea9 100644
--- a/lib/rmg/CMapGenerator.cpp
+++ b/lib/rmg/CMapGenerator.cpp
@@ -20,6 +20,8 @@ void CMapGenerator::foreach_neighbour(const int3 &pos, std::function<void(int3&
 	for(const int3 &dir : int3::getDirs())
 	{
 		int3 n = pos + dir;
+		/*important notice: perform any translation before this function is called,
+		so the actual map position is checked*/
 		if(map->isInTheMap(n))
 			foo(n);
 	}