diff --git a/include/camp/array.hpp b/include/camp/array.hpp
index 794c6fbe..71285883 100644
--- a/include/camp/array.hpp
+++ b/include/camp/array.hpp
@@ -30,6 +30,9 @@
 
 namespace camp
 {
+template <typename Tuple>
+struct tuple_size;
+
 ///
 /// Provides a portable std::array-like class.
 ///
@@ -284,6 +287,10 @@ CAMP_HOST_DEVICE constexpr void swap(array<T, N>& a, array<T, N>& b) noexcept(
   a.swap(b);
 }
 
+template <typename T, size_t N>
+struct tuple_size<array<T, N>> : ::camp::num<N> {
+};
+
 namespace detail
 {
   template <class T, std::size_t N, std::size_t... I>
diff --git a/include/camp/tuple.hpp b/include/camp/tuple.hpp
index 587bffb0..5b546602 100644
--- a/include/camp/tuple.hpp
+++ b/include/camp/tuple.hpp
@@ -19,6 +19,7 @@
 #include <sstream>
 #include <type_traits>
 
+#include "camp/array.hpp"
 #include "camp/concepts.hpp"
 #include "camp/map.hpp"