diff --git a/stl/inc/yvals_core.h b/stl/inc/yvals_core.h
index e0b3100046..132feb2a66 100644
--- a/stl/inc/yvals_core.h
+++ b/stl/inc/yvals_core.h
@@ -285,6 +285,7 @@
 // P2432R1 Fix istream_view
 // P2508R1 basic_format_string, format_string, wformat_string
 // P2520R0 move_iterator<T*> Should Be A Random-Access Iterator
+// P2588R3 barrier's Phase Completion Guarantees
 // P2711R1 Making Multi-Param Constructors Of Views explicit
 
 // _HAS_CXX20 indirectly controls:
@@ -1587,7 +1588,7 @@ _EMIT_STL_ERROR(STL1004, "C++98 unexpected() is incompatible with C++23 unexpect
 #define __cpp_lib_atomic_ref                    201806L
 #define __cpp_lib_atomic_shared_ptr             201711L
 #define __cpp_lib_atomic_wait                   201907L
-#define __cpp_lib_barrier                       201907L
+#define __cpp_lib_barrier                       202302L
 #define __cpp_lib_bind_front                    201907L
 #define __cpp_lib_bit_cast                      201806L
 #define __cpp_lib_bitops                        201907L
diff --git a/tests/libcxx/expected_results.txt b/tests/libcxx/expected_results.txt
index 19d3370a63..62b20a507e 100644
--- a/tests/libcxx/expected_results.txt
+++ b/tests/libcxx/expected_results.txt
@@ -85,6 +85,9 @@ std/utilities/charconv/charconv.to.chars/integral.pass.cpp FAIL
 # libc++ has not implemented P2505R5: "Monadic Functions for std::expected"
 std/language.support/support.limits/support.limits.general/expected.version.compile.pass.cpp FAIL
 
+# libc++ doesn't implement P2588R3 barrier's Phase Completion Guarantees
+std/language.support/support.limits/support.limits.general/barrier.version.compile.pass.cpp FAIL
+
 # libc++ doesn't implement P2711R1 Making Multi-Param Constructors Of Views explicit
 std/ranges/range.adaptors/range.drop.while/ctor.view.pass.cpp FAIL
 std/ranges/range.adaptors/range.filter/ctor.view_pred.pass.cpp FAIL
diff --git a/tests/libcxx/skipped_tests.txt b/tests/libcxx/skipped_tests.txt
index 2ddad4dc63..febeb601bc 100644
--- a/tests/libcxx/skipped_tests.txt
+++ b/tests/libcxx/skipped_tests.txt
@@ -85,6 +85,9 @@ utilities\charconv\charconv.to.chars\integral.pass.cpp
 # libc++ has not implemented P2505R5: "Monadic Functions for std::expected"
 language.support\support.limits\support.limits.general\expected.version.compile.pass.cpp
 
+# libc++ doesn't implement P2588R3 barrier's Phase Completion Guarantees
+language.support\support.limits\support.limits.general\barrier.version.compile.pass.cpp
+
 # libc++ doesn't implement P2711R1 Making Multi-Param Constructors Of Views explicit
 ranges\range.adaptors\range.drop.while\ctor.view.pass.cpp
 ranges\range.adaptors\range.filter\ctor.view_pred.pass.cpp
diff --git a/tests/std/tests/VSO_0157762_feature_test_macros/test.compile.pass.cpp b/tests/std/tests/VSO_0157762_feature_test_macros/test.compile.pass.cpp
index e266b30ed1..5544e13376 100644
--- a/tests/std/tests/VSO_0157762_feature_test_macros/test.compile.pass.cpp
+++ b/tests/std/tests/VSO_0157762_feature_test_macros/test.compile.pass.cpp
@@ -261,10 +261,10 @@ STATIC_ASSERT(__cpp_lib_atomic_wait == 201907L);
 #if _HAS_CXX20
 #ifndef __cpp_lib_barrier
 #error __cpp_lib_barrier is not defined
-#elif __cpp_lib_barrier != 201907L
-#error __cpp_lib_barrier is not 201907L
+#elif __cpp_lib_barrier != 202302L
+#error __cpp_lib_barrier is not 202302L
 #else
-STATIC_ASSERT(__cpp_lib_barrier == 201907L);
+STATIC_ASSERT(__cpp_lib_barrier == 202302L);
 #endif
 #else
 #ifdef __cpp_lib_barrier