diff --git a/include/cryptopp/OpenMPT.txt b/include/cryptopp/OpenMPT.txt
index 598e9672a39..8784213a8e5 100644
--- a/include/cryptopp/OpenMPT.txt
+++ b/include/cryptopp/OpenMPT.txt
@@ -1,5 +1,9 @@
 cryptp++ library version 8.9.0 (2023-10-01).
 The following changes have been made:
+ *  `cpu.c`has been fixed for MSVC x64 builds. See
+    <https://github.com/weidai11/cryptopp/issues/1240> and
+    <https://github.com/weidai11/cryptopp/commit/e65fa006bec60192112f0a3f23174ef0528f8cc4>.
+ *  Modifications are marked by `// OpenMPT` or `/* OpenMPT */`.
  *  Obviously, unnecessary folders and files have been removed.
  *  For building, premake is used to generate Visual Studio project files.
     See ../build/premake/ for details.
diff --git a/include/cryptopp/cpu.cpp b/include/cryptopp/cpu.cpp
index ab25bea9f1f..2ad3b46f4c4 100644
--- a/include/cryptopp/cpu.cpp
+++ b/include/cryptopp/cpu.cpp
@@ -392,7 +392,11 @@ word64 XGetBV(word32 num)
 // Use it for all MSVC-compatible compilers.
 #if defined(_M_X64) && defined(CRYPTOPP_MS_STYLE_INLINE_ASSEMBLY)
 
+#if defined(CRYPTOPP_MSC_VERSION) && (_MSC_FULL_VER >= 160040219)  /* OpenMPT */
+	return _xgetbv(num);  /* OpenMPT */
+#else  /* OpenMPT */
 	return XGETBV64(num);
+#endif  /* OpenMPT */
 
 // Required by Visual Studio 2008 and below and Clang on Windows.
 // Use it for all MSVC-compatible compilers.
@@ -450,8 +454,13 @@ bool CpuId(word32 func, word32 subfunc, word32 output[4])
 // Use it for all MSVC-compatible compilers.
 #if defined(_M_X64) && defined(CRYPTOPP_MS_STYLE_INLINE_ASSEMBLY)
 
+#if defined(CRYPTOPP_MSC_VERSION) && ((CRYPTOPP_MSC_VERSION >= 1600))  /* OpenMPT */
+	__cpuidex((int *)output, func, subfunc);  /* OpenMPT */
+	return true;  /* OpenMPT */
+#else  /* OpenMPT */
 	CPUID64(func, subfunc, output);
 	return true;
+#endif  /* OpenMPT */
 
 // Required by Visual Studio 2008 and below and Clang on Windows.
 // Use it for all MSVC-compatible compilers.