diff --git a/types/description.hpp b/types/description.hpp
index fba1aa27..7db8e848 100644
--- a/types/description.hpp
+++ b/types/description.hpp
@@ -54,6 +54,13 @@ namespace cruft::types {
     > { };
 
 
+    //-------------------------------------------------------------------------
+    template <std::size_t S, typename T>
+    struct arity_trait<
+        std::array<T,S>
+    > : public std::integral_constant<std::size_t, S> {  };
+
+
     //-------------------------------------------------------------------------
     template <typename T>
     constexpr auto arity_v = arity_trait<T>::value;