diff --git a/src/actions/AdvAction.lua b/src/actions/AdvAction.lua
index d6f0a33..2a69e5b 100644
--- a/src/actions/AdvAction.lua
+++ b/src/actions/AdvAction.lua
@@ -537,7 +537,7 @@ function _M.wheelSurfRpc(agent, data)
 	if not drawData then return end
 
 	local costs = drawData.cost:toNumMap()
-	for id, count_ in pairs(cost) do
+	for id, count_ in pairs(costs) do
 		costs[id] = count_ * count
 	end
 
--
libgit2 0.21.2