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diff --git a/boost/hana/max.hpp b/boost/hana/max.hpp
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+++ b/boost/hana/max.hpp
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+/*!
+@file
+Defines `boost::hana::max`.
+
+@copyright Louis Dionne 2013-2016
+Distributed under the Boost Software License, Version 1.0.
+(See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
+ */
+
+#ifndef BOOST_HANA_MAX_HPP
+#define BOOST_HANA_MAX_HPP
+
+#include <boost/hana/fwd/max.hpp>
+
+#include <boost/hana/concept/orderable.hpp>
+#include <boost/hana/config.hpp>
+#include <boost/hana/core/dispatch.hpp>
+#include <boost/hana/if.hpp>
+#include <boost/hana/less.hpp>
+
+
+BOOST_HANA_NAMESPACE_BEGIN
+    //! @cond
+    template <typename X, typename Y>
+    constexpr decltype(auto) max_t::operator()(X&& x, Y&& y) const {
+        using T = typename hana::tag_of<X>::type;
+        using U = typename hana::tag_of<Y>::type;
+        using Max = BOOST_HANA_DISPATCH_IF(decltype(max_impl<T, U>{}),
+            hana::Orderable<T>::value &&
+            hana::Orderable<U>::value
+        );
+
+    #ifndef BOOST_HANA_CONFIG_DISABLE_CONCEPT_CHECKS
+        static_assert(hana::Orderable<T>::value,
+        "hana::max(x, y) requires 'x' to be Orderable");
+
+        static_assert(hana::Orderable<U>::value,
+        "hana::max(x, y) requires 'y' to be Orderable");
+    #endif
+
+        return Max::apply(static_cast<X&&>(x), static_cast<Y&&>(y));
+    }
+    //! @endcond
+
+    template <typename T, typename U, bool condition>
+    struct max_impl<T, U, when<condition>> : default_ {
+        template <typename X, typename Y>
+        static constexpr decltype(auto) apply(X&& x, Y&& y) {
+            decltype(auto) cond = hana::less(x, y);
+            return hana::if_(static_cast<decltype(cond)&&>(cond),
+                static_cast<Y&&>(y),
+                static_cast<X&&>(x)
+            );
+        }
+    };
+BOOST_HANA_NAMESPACE_END
+
+#endif // !BOOST_HANA_MAX_HPP