diff --git a/include/iris/alloy/detail/tuple_impl.hpp b/include/iris/alloy/detail/tuple_impl.hpp
index 1624c89..f18b97c 100644
--- a/include/iris/alloy/detail/tuple_impl.hpp
+++ b/include/iris/alloy/detail/tuple_impl.hpp
@@ -83,7 +83,7 @@ class tuple_impl<>
 #define IRIS_ALLOY_DETAIL_FWD_INITS(n, data) \
     IRIS_PP_COMMA_IF(n) \
     IRIS_PP_CAT(IRIS_ALLOY_DETAIL_MEMBER_PREFIX, \
-                 n)(static_cast<IRIS_PP_CAT(IRIS_ALLOY_DETAIL_TEMPLATE_PARAM_2, n)>(IRIS_PP_CAT(IRIS_ALLOY_DETAIL_FUNCTION_PARAM_2, n)))
+                 n)(static_cast<IRIS_PP_CAT(IRIS_ALLOY_DETAIL_TEMPLATE_PARAM_2, n)&&>(IRIS_PP_CAT(IRIS_ALLOY_DETAIL_FUNCTION_PARAM_2, n)))
 
 #define IRIS_ALLOY_DETAIL_INITS(n, other) \
     IRIS_PP_COMMA_IF(n) \
@@ -116,7 +116,7 @@ class tuple_impl<>
 
 #define IRIS_ALLOY_DETAIL_ASSIGN_ASSIGN(n, data) \
     IRIS_PP_CAT(IRIS_ALLOY_DETAIL_MEMBER_PREFIX, n) = \
-        static_cast<IRIS_PP_CAT(IRIS_ALLOY_DETAIL_TEMPLATE_PARAM_2, n)>(IRIS_PP_CAT(IRIS_ALLOY_DETAIL_FUNCTION_PARAM_2, n));
+        static_cast<IRIS_PP_CAT(IRIS_ALLOY_DETAIL_TEMPLATE_PARAM_2, n)&&>(IRIS_PP_CAT(IRIS_ALLOY_DETAIL_FUNCTION_PARAM_2, n));
 
 #define IRIS_ALLOY_DETAIL_ASSIGN_GET(n, other) \
     IRIS_PP_CAT(IRIS_ALLOY_DETAIL_MEMBER_PREFIX, n) = alloy::get<n>(static_cast<decltype(other)>(other));
@@ -306,7 +306,7 @@ class tuple_impl<IRIS_PP_REPEAT(IRIS_ALLOY_TUPLE_LIMIT, IRIS_ALLOY_DETAIL_ARGS,
     constexpr void assign(IRIS_PP_REPEAT(IRIS_ALLOY_TUPLE_LIMIT, IRIS_ALLOY_DETAIL_FWD_PARAMS, ), Us&&... us)
     {
         IRIS_PP_REPEAT(IRIS_ALLOY_TUPLE_LIMIT, IRIS_ALLOY_DETAIL_ASSIGN_ASSIGN, )
-        rest.assign(static_cast<Us>(us)...);
+        rest.assign(static_cast<Us&&>(us)...);
     }
 
     template<IRIS_PP_REPEAT(IRIS_ALLOY_TUPLE_LIMIT, IRIS_ALLOY_DETAIL_TEMPLATE_PARAMS, IRIS_ALLOY_DETAIL_TEMPLATE_PARAM_2)>
@@ -425,7 +425,7 @@ class tuple_impl<IRIS_PP_REPEAT(IRIS_ALLOY_TUPLE_LIMIT, IRIS_ALLOY_DETAIL_ARGS,
     template<class UTuple>
     constexpr tuple_impl& operator=(UTuple&& other)
     {
-        [&, this]<std::size_t... Is>(std::index_sequence<Is...>) { assign(alloy::get<Is>(static_cast<UTuple>(other))...); }(std::index_sequence_for<Ts...>{});
+        [&, this]<std::size_t... Is>(std::index_sequence<Is...>) { assign(alloy::get<Is>(static_cast<UTuple&&>(other))...); }(std::index_sequence_for<Ts...>{});
         return *this;
     }
 
diff --git a/include/iris/alloy/tuple.hpp b/include/iris/alloy/tuple.hpp
index aeb8490..55c60fd 100644
--- a/include/iris/alloy/tuple.hpp
+++ b/include/iris/alloy/tuple.hpp
@@ -80,7 +80,7 @@ class tuple : public detail::tuple_impl<Ts...>
     template<std::size_t... Is, class UTuple>
     constexpr explicit tuple(construct_t, std::index_sequence<Is...>, UTuple&& other)
         noexcept(detail::tuple_traits<UTuple, Ts...>::all_nothrow_gettable && detail::tuple_traits<UTuple, Ts...>::all_nothrow_constructible)
-        : base_type(alloy::get<Is>(static_cast<UTuple>(other))...)
+        : base_type(alloy::get<Is>(static_cast<UTuple&&>(other))...)
     {}
 
 public:
@@ -191,7 +191,7 @@ class tuple : public detail::tuple_impl<Ts...>
 #endif
     constexpr explicit(!detail::tuple_traits<UTuple, Ts...>::all_convertible) tuple(UTuple&& other)
         noexcept(detail::tuple_traits<UTuple, Ts...>::all_nothrow_gettable && detail::tuple_traits<UTuple, Ts...>::all_nothrow_constructible)
-        : tuple(construct, std::make_index_sequence<tuple_size_v<std::remove_cvref_t<UTuple>>>{}, static_cast<UTuple>(other))
+        : tuple(construct, std::make_index_sequence<tuple_size_v<std::remove_cvref_t<UTuple>>>{}, static_cast<UTuple&&>(other))
     {}
 
 #if __cpp_lib_reference_from_temporary >= 202202L
@@ -315,7 +315,7 @@ class tuple : public detail::tuple_impl<Ts...>
     constexpr tuple& operator=(UTuple&& other)
         noexcept(detail::tuple_traits<UTuple, Ts...>::all_nothrow_assignable)
     {
-        base_type::operator=(static_cast<UTuple>(other));
+        base_type::operator=(static_cast<UTuple&&>(other));
         return *this;
     }
 
diff --git a/include/iris/alloy/utility.hpp b/include/iris/alloy/utility.hpp
index 8d4a284..d460ef5 100644
--- a/include/iris/alloy/utility.hpp
+++ b/include/iris/alloy/utility.hpp
@@ -271,6 +271,10 @@ struct tuple_assign_impl;
 template<class From, class To, std::size_t... Is>
 struct tuple_assign_impl<From, To, std::index_sequence<Is...>>
 {
+    static constexpr bool assignable = std::conjunction_v<
+        std::is_assignable<tuple_get_t<Is, To>, tuple_get_t<Is, From>>...
+    >;
+
     static constexpr bool nothrow = std::conjunction_v<
         std::conjunction<is_nothrow_gettable<Is, From>, is_nothrow_gettable<Is, To>>...,
         std::is_nothrow_assignable<tuple_get_t<Is, To>, tuple_get_t<Is, From>>...
@@ -345,9 +349,11 @@ template<std::size_t... Sizes, TupleLike Tuple>
 }
 
 template<TupleLike From, TupleLike To>
+    requires
+        (tuple_size_v<std::remove_cvref_t<From>> == tuple_size_v<std::remove_cvref_t<To>>) &&
+        detail::tuple_assign_impl<From, To>::assignable
 constexpr void tuple_assign(From&& from, To&& to) noexcept(detail::tuple_assign_impl<From, To>::nothrow)
 {
-    static_assert(tuple_size_v<std::remove_cvref_t<From>> == tuple_size_v<std::remove_cvref_t<To>>);
     detail::tuple_assign_impl<From, To>::apply(std::forward<From>(from), std::forward<To>(to));
 }