diff --git a/libs/geom/include/psemek/geom/vector.hpp b/libs/geom/include/psemek/geom/vector.hpp
index af8e11be..ce12dac5 100644
--- a/libs/geom/include/psemek/geom/vector.hpp
+++ b/libs/geom/include/psemek/geom/vector.hpp
@@ -308,6 +308,12 @@ namespace psemek::geom
 		return {std::cos(angle), std::sin(angle)};
 	}
 
+	template <typename T>
+	T angle(vector<T, 2> const & v)
+	{
+		return std::atan2(v[1], v[0]);
+	}
+
 	template <typename T, std::size_t N>
 	vector<T, N> pointwise_mult(vector<T, N> const & v0, vector<T, N> const & v1)
 	{