diff --git a/stl/inc/__msvc_print.hpp b/stl/inc/__msvc_print.hpp
index 5de74a0f2..b1b3a249d 100644
--- a/stl/inc/__msvc_print.hpp
+++ b/stl/inc/__msvc_print.hpp
@@ -8,6 +8,10 @@
 #include <yvals_core.h>
 #if _STL_COMPILER_PREPROCESSOR
 
+#ifndef __cpp_lib_concepts // note: <format> includes this header in C++20 mode
+#error The contents of <print> are available only with C++23. (Also, you should not include this internal header.)
+#endif // ^^^ !defined(__cpp_lib_concepts) ^^^
+
 #include <cstdio>
 #include <xfilesystem_abi.h>
 
diff --git a/stl/inc/ostream b/stl/inc/ostream
index 1a679cf01..de3b0a0fe 100644
--- a/stl/inc/ostream
+++ b/stl/inc/ostream
@@ -9,11 +9,11 @@
 #if _STL_COMPILER_PREPROCESSOR
 #include <ios>
 
-#if _HAS_CXX23
+#ifdef __cpp_lib_print
 #include <__msvc_filebuf.hpp>
 #include <__msvc_print.hpp>
 #include <format>
-#endif // _HAS_CXX23
+#endif // ^^^ defined(__cpp_lib_print) ^^^
 
 #pragma pack(push, _CRT_PACKING)
 #pragma warning(push, _STL_WARNING_LEVEL)
diff --git a/stl/inc/xcharconv.h b/stl/inc/xcharconv.h
index cf352799e..07f6c2f87 100644
--- a/stl/inc/xcharconv.h
+++ b/stl/inc/xcharconv.h
@@ -8,14 +8,14 @@
 #include <yvals_core.h>
 #if _STL_COMPILER_PREPROCESSOR
 
-#include <cstdint>
-#include <type_traits>
-#include <xerrc.h>
-
 #if !_HAS_CXX17
 #error The contents of <charconv> are only available with C++17. (Also, you should not include this internal header.)
 #endif // !_HAS_CXX17
 
+#include <cstdint>
+#include <type_traits>
+#include <xerrc.h>
+
 #pragma pack(push, _CRT_PACKING)
 #pragma warning(push, _STL_WARNING_LEVEL)
 #pragma warning(disable : _STL_DISABLED_WARNINGS)
diff --git a/stl/inc/xcharconv_ryu.h b/stl/inc/xcharconv_ryu.h
index fc29a3d48..343a09226 100644
--- a/stl/inc/xcharconv_ryu.h
+++ b/stl/inc/xcharconv_ryu.h
@@ -37,6 +37,10 @@
 #include <yvals_core.h>
 #if _STL_COMPILER_PREPROCESSOR
 
+#if !_HAS_CXX17
+#error The contents of <charconv> are only available with C++17. (Also, you should not include this internal header.)
+#endif // !_HAS_CXX17
+
 #include <cstring>
 #include <type_traits>
 #include <utility>
@@ -54,10 +58,6 @@
 #include _STL_INTRIN_HEADER // for _umul128() and __shiftright128()
 #endif // ^^^ intrinsics available ^^^
 
-#if !_HAS_CXX17
-#error The contents of <charconv> are only available with C++17. (Also, you should not include this internal header.)
-#endif // !_HAS_CXX17
-
 #pragma pack(push, _CRT_PACKING)
 #pragma warning(push, _STL_WARNING_LEVEL)
 #pragma warning(disable : _STL_DISABLED_WARNINGS)
diff --git a/stl/inc/xcharconv_ryu_tables.h b/stl/inc/xcharconv_ryu_tables.h
index ef01dd9e5..a8d4e5a7b 100644
--- a/stl/inc/xcharconv_ryu_tables.h
+++ b/stl/inc/xcharconv_ryu_tables.h
@@ -37,12 +37,12 @@
 #include <yvals_core.h>
 #if _STL_COMPILER_PREPROCESSOR
 
-#include <cstdint>
-
 #if !_HAS_CXX17
 #error The contents of <charconv> are only available with C++17. (Also, you should not include this internal header.)
 #endif // !_HAS_CXX17
 
+#include <cstdint>
+
 #pragma pack(push, _CRT_PACKING)
 #pragma warning(push, _STL_WARNING_LEVEL)
 #pragma warning(disable : _STL_DISABLED_WARNINGS)
diff --git a/stl/inc/xnode_handle.h b/stl/inc/xnode_handle.h
index f7f685b25..2462a506e 100644
--- a/stl/inc/xnode_handle.h
+++ b/stl/inc/xnode_handle.h
@@ -7,12 +7,13 @@
 #define _XNODE_HANDLE_H
 #include <yvals_core.h>
 #if _STL_COMPILER_PREPROCESSOR
-#include <xmemory>
 
 #if !_HAS_CXX17
 #error Node handles are only available with C++17. (Also, you should not include this internal header.)
 #endif // _HAS_CXX17
 
+#include <xmemory>
+
 #pragma pack(push, _CRT_PACKING)
 #pragma warning(push, _STL_WARNING_LEVEL)
 #pragma warning(disable : _STL_DISABLED_WARNINGS)
diff --git a/tests/std/tests/GH_001411_core_headers/test.cpp b/tests/std/tests/GH_001411_core_headers/test.cpp
index a3cbc49e9..1bf1d87f6 100644
--- a/tests/std/tests/GH_001411_core_headers/test.cpp
+++ b/tests/std/tests/GH_001411_core_headers/test.cpp
@@ -19,9 +19,9 @@
 #include <xfilesystem_abi.h>
 #endif // _HAS_CXX17
 
-#if _HAS_CXX23
+#ifdef __cpp_lib_concepts
 #include <__msvc_print.hpp>
-#endif // _HAS_CXX23
+#endif // ^^^ defined(__cpp_lib_concepts) ^^^
 
 // <__msvc_bit_utils.hpp> is included by <bit> and <limits>
 // <__msvc_iter_core.hpp> is included by <tuple>