diff --git a/luarules/gadgets/map_voidground.lua b/luarules/gadgets/map_voidground.lua
index 64cc13f90c..2038bc7188 100644
--- a/luarules/gadgets/map_voidground.lua
+++ b/luarules/gadgets/map_voidground.lua
@@ -37,7 +37,7 @@ end
 local spGetUnitDefID = Spring.GetUnitDefID
 local spGetUnitPosition = Spring.GetUnitPosition
 local spGetFeaturePosition = Spring.GetFeaturePosition
-local mapx = Game.mapSizeZ
+local mapx = Game.mapSizeX
 local mapz = Game.mapSizeZ
 
 local gaiaTeamID = Spring.GetGaiaTeamID()