diff --git a/libcxx/include/cstddef b/libcxx/include/cstddef
--- a/libcxx/include/cstddef
+++ b/libcxx/include/cstddef
@@ -35,6 +35,7 @@
 
 #include <__assert> // all public C++ headers provide the assertion handler
 #include <__config>
+#include <__type_traits/enable_if.h>
 #include <__type_traits/is_integral.h>
 #include <stddef.h>
 #include <version>
@@ -60,10 +61,7 @@
 {
 enum class byte : unsigned char {};
 
-
-template <bool> struct __enable_if_integral_imp {};
-template <> struct __enable_if_integral_imp<true> { using type = byte; };
-template <class _Tp> using _EnableByteOverload = typename __enable_if_integral_imp<__libcpp_is_integral<_Tp>::value>::type;
+template <class _Tp> using _EnableByteOverload = typename __enable_if_t<is_integral<_Tp>::value>::type;
 
 constexpr byte  operator| (byte  __lhs, byte __rhs) noexcept
 {