diff --git a/libstdc++-v3/include/bits/ranges_algo.h b/libstdc++-v3/include/bits/ranges_algo.h
index 05c0851d411..8fa4a8a9161 100644
--- a/libstdc++-v3/include/bits/ranges_algo.h
+++ b/libstdc++-v3/include/bits/ranges_algo.h
@@ -3466,9 +3466,13 @@ namespace ranges
 	      {
 		using _ValueType1 = iter_value_t<_Iter1>;
 		using _ValueType2 = iter_value_t<_Iter2>;
+		// This condition is consistent with the one in
+		// __lexicographical_compare_aux in <bits/stl_algobase.h>.
 		constexpr bool __use_memcmp
-		  = ((is_integral_v<_ValueType1> || is_pointer_v<_ValueType1>)
-		     && is_same_v<_ValueType1, _ValueType2>
+		  = (__is_byte<_ValueType1>::__value
+		     && __is_byte<_ValueType2>::__value
+		     && !__gnu_cxx::__numeric_traits<_ValueType1>::__is_signed
+		     && !__gnu_cxx::__numeric_traits<_ValueType2>::__is_signed
 		     && is_pointer_v<_Iter1>
 		     && is_pointer_v<_Iter2>
 		     && (is_same_v<_Comp, ranges::less>
diff --git a/libstdc++-v3/testsuite/25_algorithms/lexicographical_compare/93972.cc b/libstdc++-v3/testsuite/25_algorithms/lexicographical_compare/93972.cc
new file mode 100644
index 00000000000..53c4e0daddc
--- /dev/null
+++ b/libstdc++-v3/testsuite/25_algorithms/lexicographical_compare/93972.cc
@@ -0,0 +1,169 @@
+// Copyright (C) 2020 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++2a" }
+// { dg-do run { target c++2a } }
+
+#include <algorithm>
+#include <testsuite_hooks.h>
+
+using std::signed_integral;
+
+namespace ranges = std::ranges;
+
+template<signed_integral T>
+void
+test01()
+{
+  T i[] = { -1 };
+  T j[] = { 1 };
+
+  VERIFY( ranges::lexicographical_compare(i, j) );
+  VERIFY( !ranges::lexicographical_compare(i, j, ranges::greater{}) );
+
+  VERIFY( !ranges::lexicographical_compare(j, i) );
+  VERIFY( ranges::lexicographical_compare(j, i, ranges::greater{}) );
+}
+
+template<signed_integral T>
+void
+test02()
+{
+  T i[] = { -5 };
+  T j[] = { -5, 3 };
+
+  VERIFY( ranges::lexicographical_compare(i, j) );
+  VERIFY( ranges::lexicographical_compare(i, j, ranges::greater{}) );
+
+  VERIFY( !ranges::lexicographical_compare(j, i) );
+  VERIFY( !ranges::lexicographical_compare(j, i, ranges::greater{}) );
+}
+
+template<signed_integral T>
+void
+test03()
+{
+  T i[] = { -10 };
+  T j[] = { -5, 3 };
+
+  VERIFY( ranges::lexicographical_compare(i, j) );
+  VERIFY( !ranges::lexicographical_compare(i, j, ranges::greater{}) );
+
+  VERIFY( !ranges::lexicographical_compare(j, i) );
+  VERIFY( ranges::lexicographical_compare(j, i, ranges::greater{}) );
+}
+
+template<signed_integral T>
+void
+test04()
+{
+  T i[] = { -2 };
+  T j[] = { -5, 3 };
+
+  VERIFY( !ranges::lexicographical_compare(i, j) );
+  VERIFY( ranges::lexicographical_compare(i, j, ranges::greater{}) );
+
+  VERIFY( ranges::lexicographical_compare(j, i) );
+  VERIFY( !ranges::lexicographical_compare(j, i, ranges::greater{}) );
+}
+
+void
+test05()
+{
+  unsigned i[] = { 1 };
+  unsigned j[] = { 256 };
+
+  VERIFY( ranges::lexicographical_compare(i, j) );
+  VERIFY( !ranges::lexicographical_compare(i, j, ranges::greater{}) );
+
+  VERIFY( !ranges::lexicographical_compare(j, i) );
+  VERIFY( ranges::lexicographical_compare(j, i, ranges::greater{}) );
+}
+
+void
+test06()
+{
+  signed char i[] = { 100, 1 };
+  unsigned char j[] = { 100 };
+
+  VERIFY( !ranges::lexicographical_compare(i, j) );
+  VERIFY( !ranges::lexicographical_compare(i, j, ranges::greater{}) );
+
+  VERIFY( ranges::lexicographical_compare(j, i) );
+  VERIFY( ranges::lexicographical_compare(j, i, ranges::greater{}) );
+}
+
+void
+test07()
+{
+  char i[] = { 95, 1 };
+  unsigned char j[] = { 100 };
+
+  VERIFY( ranges::lexicographical_compare(i, j) );
+  VERIFY( !ranges::lexicographical_compare(i, j, ranges::greater{}) );
+
+  VERIFY( !ranges::lexicographical_compare(j, i) );
+  VERIFY( ranges::lexicographical_compare(j, i, ranges::greater{}) );
+}
+
+void
+test08()
+{
+  signed char i[] = { 112, 1 };
+  signed char j[] = { 87 };
+
+  VERIFY( !ranges::lexicographical_compare(i, j) );
+  VERIFY( ranges::lexicographical_compare(i, j, ranges::greater{}) );
+
+  VERIFY( ranges::lexicographical_compare(j, i) );
+  VERIFY( !ranges::lexicographical_compare(j, i, ranges::greater{}) );
+}
+
+void
+test09()
+{
+  char i[] = { 1 };
+  unsigned char j[] = { 100 };
+
+  VERIFY( ranges::lexicographical_compare(i, j) );
+  VERIFY( !ranges::lexicographical_compare(i, j, ranges::greater{}) );
+
+  VERIFY( !ranges::lexicographical_compare(j, i) );
+  VERIFY( ranges::lexicographical_compare(j, i, ranges::greater{}) );
+}
+
+int
+main()
+{
+  test01<signed char>();
+  test01<int>();
+
+  test02<signed char>();
+  test02<int>();
+
+  test03<signed char>();
+  test03<int>();
+
+  test04<signed char>();
+  test04<int>();
+
+  test05();
+  test06();
+  test07();
+  test08();
+  test09();
+}
