diff --git a/libcxx/include/string_view b/libcxx/include/string_view
--- a/libcxx/include/string_view
+++ b/libcxx/include/string_view
@@ -770,7 +770,7 @@
 template<class _CharT, class _Traits, int = 1>
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 bool operator==(basic_string_view<_CharT, _Traits> __lhs,
-                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
+                __type_identity_t<basic_string_view<_CharT, _Traits> > __rhs) _NOEXCEPT
 {
     if ( __lhs.size() != __rhs.size()) return false;
     return __lhs.compare(__rhs) == 0;
@@ -780,7 +780,7 @@
 // This overload is automatically generated in C++20.
 template<class _CharT, class _Traits, int = 2>
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-bool operator==(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
+bool operator==(__type_identity_t<basic_string_view<_CharT, _Traits> > __lhs,
                 basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
 {
     if ( __lhs.size() != __rhs.size()) return false;
@@ -808,7 +808,7 @@
 
 template <class _CharT, class _Traits, int = 1>
 _LIBCPP_HIDE_FROM_ABI constexpr auto operator<=>(
-    basic_string_view<_CharT, _Traits> __lhs, common_type_t<basic_string_view<_CharT, _Traits>> __rhs) noexcept {
+    basic_string_view<_CharT, _Traits> __lhs, type_identity_t<basic_string_view<_CharT, _Traits>> __rhs) noexcept {
     if constexpr (requires { typename _Traits::comparison_category; }) {
         // [string.view]/4
         static_assert(
@@ -835,7 +835,7 @@
 template<class _CharT, class _Traits, int = 1>
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 bool operator!=(basic_string_view<_CharT, _Traits> __lhs,
-                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
+                __type_identity_t<basic_string_view<_CharT, _Traits> > __rhs) _NOEXCEPT
 {
     if ( __lhs.size() != __rhs.size())
         return true;
@@ -844,7 +844,7 @@
 
 template<class _CharT, class _Traits, int = 2>
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-bool operator!=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
+bool operator!=(__type_identity_t<basic_string_view<_CharT, _Traits> > __lhs,
                 basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
 {
     if ( __lhs.size() != __rhs.size())
@@ -864,14 +864,14 @@
 template<class _CharT, class _Traits, int = 1>
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 bool operator<(basic_string_view<_CharT, _Traits> __lhs,
-                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
+                __type_identity_t<basic_string_view<_CharT, _Traits> > __rhs) _NOEXCEPT
 {
     return __lhs.compare(__rhs) < 0;
 }
 
 template<class _CharT, class _Traits, int = 2>
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-bool operator<(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
+bool operator<(__type_identity_t<basic_string_view<_CharT, _Traits> > __lhs,
                 basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
 {
     return __lhs.compare(__rhs) < 0;
@@ -889,14 +889,14 @@
 template<class _CharT, class _Traits, int = 1>
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 bool operator>(basic_string_view<_CharT, _Traits> __lhs,
-                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
+                __type_identity_t<basic_string_view<_CharT, _Traits> > __rhs) _NOEXCEPT
 {
     return __lhs.compare(__rhs) > 0;
 }
 
 template<class _CharT, class _Traits, int = 2>
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-bool operator>(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
+bool operator>(__type_identity_t<basic_string_view<_CharT, _Traits> > __lhs,
                 basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
 {
     return __lhs.compare(__rhs) > 0;
@@ -914,14 +914,14 @@
 template<class _CharT, class _Traits, int = 1>
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 bool operator<=(basic_string_view<_CharT, _Traits> __lhs,
-                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
+                __type_identity_t<basic_string_view<_CharT, _Traits> > __rhs) _NOEXCEPT
 {
     return __lhs.compare(__rhs) <= 0;
 }
 
 template<class _CharT, class _Traits, int = 2>
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-bool operator<=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
+bool operator<=(__type_identity_t<basic_string_view<_CharT, _Traits> > __lhs,
                 basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
 {
     return __lhs.compare(__rhs) <= 0;
@@ -940,14 +940,14 @@
 template<class _CharT, class _Traits, int = 1>
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 bool operator>=(basic_string_view<_CharT, _Traits> __lhs,
-                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
+                __type_identity_t<basic_string_view<_CharT, _Traits> > __rhs) _NOEXCEPT
 {
     return __lhs.compare(__rhs) >= 0;
 }
 
 template<class _CharT, class _Traits, int = 2>
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-bool operator>=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
+bool operator>=(__type_identity_t<basic_string_view<_CharT, _Traits> > __lhs,
                 basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
 {
     return __lhs.compare(__rhs) >= 0;
diff --git a/libcxx/test/std/strings/string.view/string.view.comparison/common_type_specialization.pass.cpp b/libcxx/test/std/strings/string.view/string.view.comparison/common_type_specialization.pass.cpp
new file mode 100644
--- /dev/null
+++ b/libcxx/test/std/strings/string.view/string.view.comparison/common_type_specialization.pass.cpp
@@ -0,0 +1,73 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: !stdlib=libc++ && (c++03 || c++11 || c++14)
+
+// During the review D130295 it was noticed libc++'s implementation uses
+// std::common_type. When users specialize this template for their own types the
+// comparisions would fail. This tests with a specialized std::common_type.
+
+// <string_view>
+
+#include <string_view>
+
+#include <cassert>
+#include <cstring>
+
+#include "test_comparisons.h"
+#include "test_macros.h"
+
+struct char_wrapper {
+  char c;
+};
+
+template <>
+struct std::char_traits<char_wrapper> {
+  using char_type = char_wrapper;
+
+  static bool eq(char_wrapper lhs, char_wrapper rhs) { return lhs.c == rhs.c; }
+
+  static size_t length(const char_wrapper* a) {
+    static_assert(sizeof(char_wrapper) == 1, "strlen requires this");
+    return std::strlen(reinterpret_cast<const char*>(a));
+  }
+
+  static int compare(const char_wrapper* lhs, const char_wrapper* rhs, std::size_t count) {
+    return std::char_traits<char>::compare(
+        reinterpret_cast<const char*>(lhs), reinterpret_cast<const char*>(rhs), count);
+  }
+};
+
+using WrappedSV = std::basic_string_view<char_wrapper, std::char_traits<char_wrapper> >;
+
+// std::common_type can be specialized and not have a typedef-name member type.
+template <>
+struct std::common_type<WrappedSV, WrappedSV> {};
+
+struct convertible_to_string_view {
+  WrappedSV sv;
+  convertible_to_string_view(const char_wrapper* a) : sv(a) {}
+  operator WrappedSV() const { return sv; }
+};
+
+template <class T, class U>
+void test() {
+  char_wrapper a[] = {{'a'}, {'b'}, {'c'}, {'\0'}};
+
+  assert((testComparisons(T(a), U(a), true, false)));
+
+#if TEST_STD_VER > 17
+  assert((testOrder(T(a), U(a), std::weak_ordering::equivalent)));
+#endif
+}
+
+int main(int, char**) {
+  test<WrappedSV, convertible_to_string_view>();
+
+  return 0;
+}