diff --git a/libs/geom/include/psemek/geom/quaternion.hpp b/libs/geom/include/psemek/geom/quaternion.hpp
index 1fc0f5c5..89b49175 100644
--- a/libs/geom/include/psemek/geom/quaternion.hpp
+++ b/libs/geom/include/psemek/geom/quaternion.hpp
@@ -18,12 +18,9 @@ namespace psemek::geom
 		static quaternion<T> vector(geom::vector<T, 3> const & v);
 		static quaternion<T> rotation(T angle, geom::vector<T, 3> const & axis);
 
-		template <typename ... Args>
-		quaternion(Args && ... args)
-			: coords{ static_cast<T>(std::forward<Args>(args))... }
-		{
-			static_assert(sizeof...(Args) == 4);
-		}
+		quaternion(geom::vector<T, 4> const & v)
+			: coords{v}
+		{}
 
 		T & operator[] (std::size_t i) { return coords[i]; }
 		T const & operator[] (std::size_t i) const { return coords[i]; }
@@ -35,25 +32,25 @@ namespace psemek::geom
 	template <typename T>
 	quaternion<T> quaternion<T>::zero()
 	{
-		return quaternion<T>{T(0), T(0), T(0), T(0)};
+		return quaternion<T>{geom::vector<T, 4>::zero()};
 	}
 
 	template <typename T>
 	quaternion<T> quaternion<T>::identity()
 	{
-		return quaternion<T>{T(1), T(0), T(0), T(0)};
+		return quaternion<T>{{T(1), T(0), T(0), T(0)}};
 	}
 
 	template <typename T>
 	quaternion<T> quaternion<T>::scalar(T value)
 	{
-		return {value, T(0), T(0), T(0)};
+		return {{value, T(0), T(0), T(0)}};
 	}
 
 	template <typename T>
 	quaternion<T> quaternion<T>::vector(geom::vector<T, 3> const & v)
 	{
-		return {T(0), v[0], v[1], v[2]};
+		return {{T(0), v[0], v[1], v[2]}};
 	}
 
 	template <typename T>
@@ -62,7 +59,7 @@ namespace psemek::geom
 		auto const c = std::cos(angle / 2);
 		auto const s = std::sin(angle / 2);
 
-		return quaternion<T>{c, s * axis[0], s * axis[1], s * axis[2]};
+		return quaternion<T>{{c, s * axis[0], s * axis[1], s * axis[2]}};
 	}
 
 	template <typename T>