diff --git a/libs/geom/include/psemek/geom/box.hpp b/libs/geom/include/psemek/geom/box.hpp
index 6496775e..3c04077f 100644
--- a/libs/geom/include/psemek/geom/box.hpp
+++ b/libs/geom/include/psemek/geom/box.hpp
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <psemek/geom/detail/array.hpp>
 #include <psemek/geom/interval.hpp>
 #include <psemek/geom/point.hpp>
 
@@ -9,7 +10,7 @@ namespace psemek::geom
 	template <typename T, std::size_t N>
 	struct box
 	{
-		interval<T> axes[N];
+		detail::array<interval<T>, N>::type axes;
 
 		using point_type = point<T, N>;
 		using vector_type = vector<T, N>;
diff --git a/libs/geom/include/psemek/geom/detail/array.hpp b/libs/geom/include/psemek/geom/detail/array.hpp
new file mode 100644
index 00000000..0fb73944
--- /dev/null
+++ b/libs/geom/include/psemek/geom/detail/array.hpp
@@ -0,0 +1,33 @@
+#pragma once
+
+#include <exception>
+
+namespace psemek::geom::detail
+{
+
+	struct empty_array_exception
+		: std::exception
+	{
+		char const * what() const noexcept
+		{
+			return "Attempt to index a zero vector";
+		}
+	};
+
+	template <typename T, std::size_t N>
+	struct array
+	{
+		using type = T[N];
+	};
+
+	template <typename T>
+	struct array<T, 0>
+	{
+		struct type
+		{
+			T const & operator[](std::size_t) const { throw empty_array_exception{}; }
+			T & operator[](std::size_t) { throw empty_array_exception{}; }
+		};
+	};
+
+}
diff --git a/libs/geom/include/psemek/geom/matrix.hpp b/libs/geom/include/psemek/geom/matrix.hpp
index dd35a9de..3f8d7059 100644
--- a/libs/geom/include/psemek/geom/matrix.hpp
+++ b/libs/geom/include/psemek/geom/matrix.hpp
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <psemek/geom/detail/array.hpp>
 #include <psemek/geom/vector.hpp>
 
 #include <algorithm>
@@ -15,7 +16,7 @@ namespace psemek::geom
 
 		using scalar_type = T;
 
-		T coords[R * C];
+		detail::array<T, R * C>::type coords;
 
 		T * operator[](std::size_t i)
 		{
diff --git a/libs/geom/include/psemek/geom/point.hpp b/libs/geom/include/psemek/geom/point.hpp
index 040ad9f8..51dff048 100644
--- a/libs/geom/include/psemek/geom/point.hpp
+++ b/libs/geom/include/psemek/geom/point.hpp
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <psemek/geom/detail/array.hpp>
 #include <psemek/geom/vector.hpp>
 
 namespace psemek::geom
@@ -12,7 +13,7 @@ namespace psemek::geom
 
 		using scalar_type = T;
 
-		T coords[N];
+		detail::array<T, N>::type coords;
 
 		point() = default;
 		point(point const &) = default;
diff --git a/libs/geom/include/psemek/geom/vector.hpp b/libs/geom/include/psemek/geom/vector.hpp
index f4947f5d..b44aec6c 100644
--- a/libs/geom/include/psemek/geom/vector.hpp
+++ b/libs/geom/include/psemek/geom/vector.hpp
@@ -1,5 +1,7 @@
 #pragma once
 
+#include <psemek/geom/detail/array.hpp>
+
 #include <cstddef>
 #include <utility>
 #include <type_traits>
@@ -9,27 +11,6 @@
 namespace psemek::geom
 {
 
-	namespace detail
-	{
-
-		template <typename T, std::size_t N>
-		struct empty_array_helper
-		{
-			using type = T[N];
-		};
-
-		template <typename T>
-		struct empty_array_helper<T, 0>
-		{
-			struct type
-			{
-				T const & operator[](std::size_t) const { throw std::runtime_error("Attempt to index a zero vector"); }
-				T & operator[](std::size_t) { throw std::runtime_error("Attempt to index a zero vector"); }
-			};
-		};
-
-	}
-
 	template <typename T, std::size_t N>
 	struct vector
 	{
@@ -37,7 +18,7 @@ namespace psemek::geom
 
 		using scalar_type = T;
 
-		detail::empty_array_helper<T, N>::type coords;
+		detail::array<T, N>::type coords;
 
 		vector() = default;
 		vector(vector const &) = default;