diff --git a/libs/math/include/psemek/math/matrix.hpp b/libs/math/include/psemek/math/matrix.hpp
index 21662f82..49bee094 100644
--- a/libs/math/include/psemek/math/matrix.hpp
+++ b/libs/math/include/psemek/math/matrix.hpp
@@ -437,16 +437,34 @@ namespace psemek::math
 	T frobenius_norm_sqr(matrix<T, R, C> const & m)
 	{
 		T r{0};
-		for (std::size_t i = 0; i < m.rows(); ++i)
-			for (std::size_t j = 0; j < m.columns(); ++j)
-				r += sqr(m[i][j]);
+		for (auto const & value : m.values())
+			r += sqr(value);
+		return r;
+	}
+
+	template <typename T, std::size_t R, std::size_t C>
+	T linf_norm(matrix<T, R, C> const & m)
+	{
+		using std::abs;
+		using std::max;
+		T r = abs(m[0][0]);
+		for (auto const & value : m.values())
+			make_max(r, abs(value));
 		return r;
 	}
 
 	template <typename T, std::size_t R, std::size_t C>
 	T frobenius_norm(matrix<T, R, C> const & m)
 	{
-		return std::sqrt(frobenius_norm_sqr(m));
+		T const max = linf_norm(m);
+		if (max == T(0)) return max;
+
+		T sum{};
+		for (auto const & value : m.values())
+			sum += sqr(value / max);
+
+		using std::sqrt;
+		return max * sqrt(sum);
 	}
 
 	template <typename T, std::size_t R, std::size_t C>