diff --git a/include/sol/detail/pairs.hpp b/include/sol/detail/pairs.hpp
index fb88faa7..f6776cd0 100644
--- a/include/sol/detail/pairs.hpp
+++ b/include/sol/detail/pairs.hpp
@@ -28,6 +28,7 @@
 
 #include <sol/stack.hpp>
 #include <sol/stack_reference.hpp>
+#include <sol/assert.hpp>
 
 namespace sol { namespace stack { namespace stack_detail {
 
diff --git a/include/sol/stack_field.hpp b/include/sol/stack_field.hpp
index 9a184e0b..70b0903a 100644
--- a/include/sol/stack_field.hpp
+++ b/include/sol/stack_field.hpp
@@ -33,11 +33,11 @@ namespace sol { namespace stack {
 
 	namespace stack_detail {
 		template <typename T, bool global, bool raw>
-		inline constexpr bool is_get_direct_tableless_v = (global && !raw && meta::is_c_str_v<T>);
+		inline constexpr bool is_get_direct_tableless_v = (global && !raw && meta::is_c_str_or_string_v<T>);
 
 		template <typename T, bool global, bool raw>
 		inline constexpr bool is_get_direct_v = (is_get_direct_tableless_v<T, global, raw>) // cf-hack
-			|| (!global && !raw && (meta::is_c_str_v<T> || meta::is_string_of_v<T, char>)) // cf-hack
+			|| (!global && !raw && (meta::is_c_str_or_string_v<T> || meta::is_string_of_v<T, char>)) // cf-hack
 			|| (!global && raw && (std::is_integral_v<T> && !std::is_same_v<T, bool>))
 #if SOL_LUA_VERSION_I_ >= 503
 			|| (!global && !raw && (std::is_integral_v<T> && !std::is_same_v<T, bool>))
@@ -48,11 +48,11 @@ namespace sol { namespace stack {
 			;
 
 		template <typename T, bool global, bool raw>
-		inline constexpr bool is_set_direct_tableless_v = (global && !raw && meta::is_c_str_v<T>);
+		inline constexpr bool is_set_direct_tableless_v = (global && !raw && meta::is_c_str_or_string_v<T>);
 
 		template <typename T, bool global, bool raw>
 		inline constexpr bool is_set_direct_v = (is_set_direct_tableless_v<T, global, raw>) // cf-hack
-			|| (!global && !raw && (meta::is_c_str_v<T> || meta::is_string_of_v<T, char>)) // cf-hack
+			|| (!global && !raw && (meta::is_c_str_or_string_v<T> || meta::is_string_of_v<T, char>)) // cf-hack
 			|| (!global && raw && (std::is_integral_v<T> && !std::is_same_v<T, bool>))     // cf-hack
 #if SOL_LUA_VERSION_I_ >= 503
 			|| (!global && !raw && (std::is_integral_v<T> && !std::is_same_v<T, bool>))
@@ -107,7 +107,7 @@ namespace sol { namespace stack {
 				}
 			}
 			else {
-				if constexpr (meta::is_c_str_v<T>) {
+				if constexpr (meta::is_c_str_or_string_v<T>) {
 					if constexpr (global) {
 						(void)tableindex;
 						lua_getglobal(L, &key[0]);
@@ -212,7 +212,7 @@ namespace sol { namespace stack {
 				}
 			}
 			else {
-				if constexpr (meta::is_c_str_v<T> || meta::is_string_of_v<T, char>) {
+				if constexpr (meta::is_c_str_v<T>) {
 					if constexpr (global) {
 						push(L, std::forward<Value>(value));
 						lua_setglobal(L, &key[0]);
diff --git a/include/sol/traits.hpp b/include/sol/traits.hpp
index fd062945..3e7ff4ce 100644
--- a/include/sol/traits.hpp
+++ b/include/sol/traits.hpp
@@ -678,8 +678,7 @@ namespace sol { namespace meta {
 	struct is_pair<std::pair<T1, T2>> : std::true_type { };
 
 	template <typename T, typename Char>
-	using is_c_str_of = any<std::is_same<T, const Char*>, std::is_same<T, Char const* const>, std::is_same<T, Char*>, is_string_of<T, Char>,
-		is_string_literal_array_of<T, Char>>;
+	using is_c_str_of = any<std::is_same<T, const Char*>, std::is_same<T, Char const* const>, std::is_same<T, Char*>, is_string_literal_array_of<T, Char>>;
 
 	template <typename T, typename Char>
 	constexpr inline bool is_c_str_of_v = is_c_str_of<T, Char>::value;
@@ -690,6 +689,18 @@ namespace sol { namespace meta {
 	template <typename T>
 	constexpr inline bool is_c_str_v = is_c_str<T>::value;
 
+	template <typename T, typename Char>
+	using is_c_str_or_string_of = any<is_c_str_of<T, Char>, is_string_of<T, Char>>;
+
+	template <typename T, typename Char>
+	constexpr inline bool is_c_str_or_string_of_v = is_c_str_or_string_of<T, Char>::value;
+
+	template <typename T>
+	using is_c_str_or_string = is_c_str_or_string_of<T, char>;
+
+	template <typename T>
+	constexpr inline bool is_c_str_or_string_v = is_c_str<T>::value;
+
 	template <typename T>
 	struct is_move_only : all<neg<std::is_reference<T>>, neg<std::is_copy_constructible<unqualified_t<T>>>, std::is_move_constructible<unqualified_t<T>>> { };
 
diff --git a/include/sol/usertype_storage.hpp b/include/sol/usertype_storage.hpp
index fdfac5ff..b8475134 100644
--- a/include/sol/usertype_storage.hpp
+++ b/include/sol/usertype_storage.hpp
@@ -66,11 +66,11 @@ namespace sol { namespace u_detail {
 	template <typename K, typename Fq, typename T = void>
 	struct binding : binding_base {
 		using uF = meta::unqualified_t<Fq>;
-		using F = meta::conditional_t<meta::is_c_str_of_v<uF, char>
+		using F = meta::conditional_t<meta::is_c_str_or_string_of_v<uF, char>
 #if SOL_IS_ON(SOL_CHAR8_T_I_)
-			     || meta::is_c_str_of_v<uF, char8_t>
+			     || meta::is_c_str_or_string_of_v<uF, char8_t>
 #endif
-			     || meta::is_c_str_of_v<uF, char16_t> || meta::is_c_str_of_v<uF, char32_t> || meta::is_c_str_of_v<uF, wchar_t>,
+			     || meta::is_c_str_or_string_of_v<uF, char16_t> || meta::is_c_str_or_string_of_v<uF, char32_t> || meta::is_c_str_or_string_of_v<uF, wchar_t>,
 			std::add_pointer_t<std::add_const_t<std::remove_all_extents_t<Fq>>>, std::decay_t<Fq>>;
 		F data_;