diff --git a/src/Library/TypeLibrary.cpp b/src/Library/TypeLibrary.cpp
index b4ee41c..220a16b 100644
--- a/src/Library/TypeLibrary.cpp
+++ b/src/Library/TypeLibrary.cpp
@@ -1,14 +1,11 @@
 #include "TypeLibrary.hpp"
 #include <Arbutils/Assert.hpp>
+#include <numeric>
 
 using namespace CreatureLib::Library;
 
 float TypeLibrary::GetEffectiveness(uint8_t attacking, const List<uint8_t>& defensive) const {
-    auto eff = 1;
-    for (auto def : defensive) {
-        eff *= GetSingleEffectiveness(attacking, def);
-    }
-    return eff;
+    return std::accumulate(defensive.begin(), defensive.end(), (float)1, std::multiplies<float>());
 }
 
 float TypeLibrary::GetSingleEffectiveness(uint8_t attacking, uint8_t defensive) const {