diff --git a/include/pybind11/detail/common.h b/include/pybind11/detail/common.h
index 862451f..5d9162b 100644
--- a/include/pybind11/detail/common.h
+++ b/include/pybind11/detail/common.h
@@ -153,10 +153,6 @@
 #  pragma warning(push)
 // C4505: 'PySlice_GetIndicesEx': unreferenced local function has been removed (PyPy only)
 #  pragma warning(disable: 4505)
-#  if defined(_DEBUG) && !defined(Py_DEBUG)
-#    define PYBIND11_DEBUG_MARKER
-#    undef _DEBUG
-#  endif
 #endif
 
 // https://en.cppreference.com/w/c/chrono/localtime
diff --git a/include/pybind11/pybind11.h b/include/pybind11/pybind11.h
index 5d86154..c0f0741 100644
--- a/include/pybind11/pybind11.h
+++ b/include/pybind11/pybind11.h
@@ -10,11 +10,6 @@
 
 #pragma once
 
-// Bug in MSVC 2022 requiring this file first
-#if defined(_MSC_VER) && (_MSC_VER >= 1930)
-#include <corecrt.h>
-#endif
-
 #include "attr.h"
 #include "gil.h"
 #include "options.h"