diff --git a/include/continuable/continuable-traverse.hpp b/include/continuable/continuable-traverse.hpp
index f1aafaf..7e146f1 100644
--- a/include/continuable/continuable-traverse.hpp
+++ b/include/continuable/continuable-traverse.hpp
@@ -71,7 +71,10 @@ namespace cti {
 ///
 /// \since        3.0.0
 template <typename Mapper, typename... T>
-decltype(auto) map_pack(Mapper&& mapper, T&&... pack) {
+auto map_pack(Mapper&& mapper, T&&... pack)
+    -> decltype(detail::traversal::transform(
+        detail::traversal::strategy_remap_tag{}, std::forward<Mapper>(mapper),
+        std::forward<T>(pack)...)) {
   return detail::traversal::transform(detail::traversal::strategy_remap_tag{},
                                       std::forward<Mapper>(mapper),
                                       std::forward<T>(pack)...);
@@ -83,7 +86,7 @@ decltype(auto) map_pack(Mapper&& mapper, T&&... pack) {
 ///
 /// \since 3.0.0
 template <typename... T>
-constexpr decltype(auto) spread_this(T&&... args) noexcept(
+constexpr auto spread_this(T&&... args) noexcept(
     noexcept(std::make_tuple(std::forward<T>(args)...))) {
   using type = detail::traversal::spreading::spread_box<std::decay_t<T>...>;
   return type(std::make_tuple(std::forward<T>(args)...));
diff --git a/include/continuable/detail/traverse.hpp b/include/continuable/detail/traverse.hpp
index ec88031..10e43a8 100644
--- a/include/continuable/detail/traverse.hpp
+++ b/include/continuable/detail/traverse.hpp
@@ -797,7 +797,10 @@ public:
 
   /// \copybrief try_traverse
   template <typename T>
-  decltype(auto) init_traverse(strategy_remap_tag, T&& element) {
+  auto init_traverse(strategy_remap_tag, T&& element)
+      -> decltype(spreading::unpack_or_void(
+          std::declval<mapping_helper>().try_traverse(strategy_remap_tag{},
+                                                      std::declval<T>()))) {
     return spreading::unpack_or_void(
         try_traverse(strategy_remap_tag{}, std::forward<T>(element)));
   }
@@ -809,8 +812,15 @@ public:
   /// Calls the traversal method for every element in the pack,
   /// and returns a tuple containing the remapped content.
   template <typename First, typename Second, typename... T>
-  decltype(auto) init_traverse(strategy_remap_tag strategy, First&& first,
-                     Second&& second, T&&... rest) {
+  auto init_traverse(strategy_remap_tag strategy, First&& first,
+                     Second&& second, T&&... rest)
+      -> decltype(spreading::tupelize_or_void(
+          std::declval<mapping_helper>().try_traverse(
+              strategy, std::forward<First>(first)),
+          std::declval<mapping_helper>().try_traverse(
+              strategy, std::forward<Second>(second)),
+          std::declval<mapping_helper>().try_traverse(
+              strategy, std::forward<T>(rest))...)) {
     return spreading::tupelize_or_void(
         try_traverse(strategy, std::forward<First>(first)),
         try_traverse(strategy, std::forward<Second>(second)),
@@ -832,7 +842,9 @@ public:
 
 /// Traverses the given pack with the given mapper and strategy
 template <typename Strategy, typename Mapper, typename... T>
-decltype(auto) transform(Strategy strategy, Mapper&& mapper, T&&... pack) {
+auto transform(Strategy strategy, Mapper&& mapper, T&&... pack) -> decltype(
+    std::declval<mapping_helper<Strategy, typename std::decay<Mapper>::type>>()
+        .init_traverse(strategy, std::forward<T>(pack)...)) {
   mapping_helper<Strategy, typename std::decay<Mapper>::type> helper(
       std::forward<Mapper>(mapper));
   return helper.init_traverse(strategy, std::forward<T>(pack)...);