Index: include/type_traits
===================================================================
--- include/type_traits
+++ include/type_traits
@@ -3172,6 +3172,14 @@
 false_type
 __is_constructible2_test(__any, _A0&, _A1&);
 
+template <class _Tp, class _A0, class _A1, class _A2>
+decltype((_Tp(_VSTD::declval<_A0>(), _VSTD::declval<_A1>(), _VSTD::declval<_A2>()), true_type()))
+__is_constructible3_test(_Tp&, _A0&, _A1&, _A2&);
+
+template <class _A0, class _A1, class _A2>
+false_type
+__is_constructible3_test(__any, _A0&, _A1&, _A2&);
+
 template <bool, class _Tp>
 struct __is_constructible0_imp // false, _Tp is not a scalar
     : public common_type
@@ -3196,6 +3204,14 @@
              >::type
     {};
 
+template <bool, class _Tp, class _A0, class _A1, class _A2>
+struct __is_constructible3_imp // false, _Tp is not a scalar
+    : public common_type
+             <
+                 decltype(__is_constructible3_test(declval<_Tp&>(), declval<_A0>(), declval<_A1>(), declval<_A2>()))
+             >::type
+    {};
+
 //      handle scalars and reference types
 
 //      Scalars are default constructible, references are not
@@ -3215,6 +3231,11 @@
     : public false_type
     {};
 
+template <class _Tp, class _A0, class _A1, class _A2>
+struct __is_constructible3_imp<true, _Tp, _A0, _A1, _A2>
+    : public false_type
+    {};
+
 //      Treat scalars and reference types separately
 
 template <bool, class _Tp>
@@ -3235,6 +3256,12 @@
                                 _Tp, _A0, _A1>
     {};
 
+template <bool, class _Tp, class _A0, class _A1, class _A2>
+struct __is_constructible3_void_check
+    : public __is_constructible3_imp<is_scalar<_Tp>::value || is_reference<_Tp>::value,
+                                _Tp, _A0, _A1, _A2>
+    {};
+
 //      If any of T or Args is void, is_constructible should be false
 
 template <class _Tp>
@@ -3252,17 +3279,24 @@
     : public false_type
     {};
 
+template <class _Tp, class _A0, class _A1, class _A2>
+struct __is_constructible3_void_check<true, _Tp, _A0, _A1, _A2>
+    : public false_type
+    {};
+
 //      is_constructible entry point
 
 template <class _Tp, class _A0 = __is_construct::__nat,
-                     class _A1 = __is_construct::__nat>
+                     class _A1 = __is_construct::__nat,
+                     class _A2 = __is_construct::__nat>
 struct _LIBCPP_TEMPLATE_VIS is_constructible
-    : public __is_constructible2_void_check<is_void<_Tp>::value
+    : public __is_constructible3_void_check<is_void<_Tp>::value
                                         || is_abstract<_Tp>::value
                                         || is_function<_Tp>::value
                                         || is_void<_A0>::value
-                                        || is_void<_A1>::value,
-                                           _Tp, _A0, _A1>
+                                        || is_void<_A1>::value
+                                        || is_void<_A2>::value,
+                                           _Tp, _A0, _A1, _A2>
     {};
 
 template <class _Tp>
@@ -3282,6 +3316,16 @@
                                            _Tp, _A0>
     {};
 
+template <class _Tp, class _A0, class _A1>
+struct _LIBCPP_TEMPLATE_VIS is_constructible<_Tp, _A0, _A1, __is_construct::__nat>
+    : public __is_constructible2_void_check<is_void<_Tp>::value
+                                        || is_abstract<_Tp>::value
+                                        || is_function<_Tp>::value
+                                        || is_void<_A0>::value
+                                        || is_void<_A1>::value,
+                                           _Tp, _A0, _A1>
+    {};
+
 //      Array types are default constructible if their element type
 //      is default constructible
 
@@ -3300,6 +3344,11 @@
     : public false_type
     {};
 
+template <class _Ap, size_t _Np, class _A0, class _A1, class _A2>
+struct __is_constructible3_imp<false, _Ap[_Np], _A0, _A1, _A2>
+    : public false_type
+    {};
+
 //      Incomplete array types are not constructible
 
 template <class _Ap>
@@ -3314,6 +3363,11 @@
 
 template <class _Ap, class _A0, class _A1>
 struct __is_constructible2_imp<false, _Ap[], _A0, _A1>
+    : public false_type
+    {};
+
+template <class _Ap, class _A0, class _A1, class _A2>
+struct __is_constructible3_imp<false, _Ap[], _A0, _A1, _A2>
     : public false_type
     {};
 
Index: test/std/utilities/meta/meta.unary/meta.unary.prop/is_constructible.pass.cpp
===================================================================
--- test/std/utilities/meta/meta.unary/meta.unary.prop/is_constructible.pass.cpp
+++ test/std/utilities/meta/meta.unary/meta.unary.prop/is_constructible.pass.cpp
@@ -30,6 +30,7 @@
 {
     explicit A(int);
     A(int, double);
+    A(int, long, double);
 #if TEST_STD_VER >= 11
 private:
 #endif
@@ -106,6 +107,16 @@
 #endif
 }
 
+template <class T, class A0, class A1, class A2>
+void test_is_constructible()
+{
+    static_assert(( std::is_constructible<T, A0, A1, A2>::value), "");
+    LIBCPP11_STATIC_ASSERT((std::__libcpp_is_constructible<T, A0, A1, A2>::type::value), "");
+#if TEST_STD_VER > 14
+    static_assert(( std::is_constructible_v<T, A0, A1, A2>), "");
+#endif
+}
+
 template <class T>
 void test_is_not_constructible()
 {
@@ -146,6 +157,7 @@
     test_is_constructible<int, const int> ();
     test_is_constructible<A, int> ();
     test_is_constructible<A, int, double> ();
+    test_is_constructible<A, int, long, double> ();
     test_is_constructible<int&, int&> ();
 
     test_is_not_constructible<A> ();