diff --git a/dice.cpp b/dice.cpp
index 17193a0..34bf2b8 100644
--- a/dice.cpp
+++ b/dice.cpp
@@ -15,6 +15,7 @@ void const_roll_table::init(const std::vector<int>& weights)
 	std::queue<int> small;
 	std::queue<int> large;
 	std::vector<int> w;
+	w.reserve(size);
 	for (int i : weights)
 	{
 		w.push_back(i * size);