diff --git a/Siv3D/include/Siv3D/DiscreteDistribution.hpp b/Siv3D/include/Siv3D/DiscreteDistribution.hpp
index 5b153d35b..e87a841b6 100644
--- a/Siv3D/include/Siv3D/DiscreteDistribution.hpp
+++ b/Siv3D/include/Siv3D/DiscreteDistribution.hpp
@@ -92,11 +92,11 @@ namespace s3d
 
 	template <class Type, class URBG>
 	[[nodiscard]]
-	inline decltype(auto) DiscreteSample(std::initializer_list<Type> ilist, DiscreteDistribution& weight, URBG&& urbg);
+	inline auto DiscreteSample(std::initializer_list<Type> ilist, DiscreteDistribution& weight, URBG&& urbg);
 	
 	template <class Type>
 	[[nodiscard]]
-	inline decltype(auto) DiscreteSample(std::initializer_list<Type> ilist, DiscreteDistribution& weight);
+	inline auto DiscreteSample(std::initializer_list<Type> ilist, DiscreteDistribution& weight);
 }
 
 # include "detail/DiscreteDistribution.ipp"
diff --git a/Siv3D/include/Siv3D/detail/DiscreteDistribution.ipp b/Siv3D/include/Siv3D/detail/DiscreteDistribution.ipp
index aaf61c37f..1fb298f72 100644
--- a/Siv3D/include/Siv3D/detail/DiscreteDistribution.ipp
+++ b/Siv3D/include/Siv3D/detail/DiscreteDistribution.ipp
@@ -106,14 +106,14 @@ namespace s3d
 	}
 
 	template <class Type, class URBG>
-	inline decltype(auto) DiscreteSample(std::initializer_list<Type> ilist, DiscreteDistribution& weight, URBG&& urbg)
+	inline auto DiscreteSample(std::initializer_list<Type> ilist, DiscreteDistribution& weight, URBG&& urbg)
 	{
 		assert(ilist.size() != 0);
 		return *(ilist.begin() + weight(std::forward<URBG>(urbg)));
 	}
 
 	template <class Type>
-	inline decltype(auto) DiscreteSample(std::initializer_list<Type> ilist, DiscreteDistribution& weight)
+	inline auto DiscreteSample(std::initializer_list<Type> ilist, DiscreteDistribution& weight)
 	{
 		return DiscreteSample(ilist, weight, GetDefaultRNG());
 	}