diff --git a/src/mcts.jl b/src/mcts.jl
index 1896444..c37d9f2 100644
--- a/src/mcts.jl
+++ b/src/mcts.jl
@@ -286,7 +286,7 @@ julia>
 
 # Signature
 """
-function simulate(node::MCTSNode, transition::Function, args...; 
+function simulate(node::MCTSNode, transition::Function, args::NamedTuple; 
   maxdepth::Integer=3, totalsample::Integer=3
   )::Union{Tuple{Number, Dict{Symbol, <:Any}}, Tuple{Number, Nothing}}