diff --git a/winbuild/build.rst b/winbuild/build.rst
index b30a94226d7..661c5a5ecea 100644
--- a/winbuild/build.rst
+++ b/winbuild/build.rst
@@ -24,7 +24,7 @@ Download and install:
 * `CMake 3.12 or newer <https://cmake.org/download/>`_
   (also available as Visual Studio component C++ CMake tools for Windows)
 
-* `NASM <https://www.nasm.us/pub/nasm/releasebuilds/?C=M;O=D>`_
+* x86/x64: `NASM <https://www.nasm.us/pub/nasm/releasebuilds/?C=M;O=D>`_
 
 Any version of Visual Studio 2017 or newer should be supported,
 including Visual Studio 2017 Community, or Build Tools for Visual Studio 2019.
@@ -42,8 +42,8 @@ behaviour of ``build_prepare.py``:
   If ``PYTHON`` is unset, the version of Python used to run
   ``build_prepare.py`` will be used. If only ``PYTHON`` is set,
   ``EXECUTABLE`` defaults to ``python.exe``.
-* ``ARCHITECTURE`` is used to select a ``x86`` or ``x64`` build. By default,
-  uses same architecture as the version of Python used to run ``build_prepare.py``.
+* ``ARCHITECTURE`` is used to select a ``x86``, ``x64`` or ``ARM64``build.
+  By default, uses same architecture as the version of Python used to run ``build_prepare.py``.
   is used.
 * ``PILLOW_BUILD`` can be used to override the ``winbuild\build`` directory
   path, used to store generated build scripts and compiled libraries.
diff --git a/winbuild/build_prepare.py b/winbuild/build_prepare.py
index 4d9f7921131..01f1bac298b 100644
--- a/winbuild/build_prepare.py
+++ b/winbuild/build_prepare.py
@@ -1,4 +1,5 @@
 import os
+import platform
 import shutil
 import struct
 import subprocess
@@ -93,6 +94,7 @@ def cmd_msbuild(
 architectures = {
     "x86": {"vcvars_arch": "x86", "msbuild_arch": "Win32"},
     "x64": {"vcvars_arch": "x86_amd64", "msbuild_arch": "x64"},
+    "ARM64": {"vcvars_arch": "x86_arm64", "msbuild_arch": "ARM64"},
 }
 
 header = [
@@ -223,21 +225,21 @@ def cmd_msbuild(
         "filename": "lcms2-2.13.tar.gz",
         "dir": "lcms2-2.13",
         "patch": {
-            r"Projects\VC2017\lcms2_static\lcms2_static.vcxproj": {
+            r"Projects\VC2019\lcms2_static\lcms2_static.vcxproj": {
                 # default is /MD for x86 and /MT for x64, we need /MD always
                 "<RuntimeLibrary>MultiThreaded</RuntimeLibrary>": "<RuntimeLibrary>MultiThreadedDLL</RuntimeLibrary>",  # noqa: E501
                 # retarget to default toolset (selected by vcvarsall.bat)
-                "<PlatformToolset>v141</PlatformToolset>": "<PlatformToolset>$(DefaultPlatformToolset)</PlatformToolset>",  # noqa: E501
+                "<PlatformToolset>v142</PlatformToolset>": "<PlatformToolset>$(DefaultPlatformToolset)</PlatformToolset>",  # noqa: E501
                 # retarget to latest (selected by vcvarsall.bat)
-                "<WindowsTargetPlatformVersion>10.0.17134.0</WindowsTargetPlatformVersion>": "<WindowsTargetPlatformVersion>$(WindowsSDKVersion)</WindowsTargetPlatformVersion>",  # noqa: E501
+                "<WindowsTargetPlatformVersion>10.0</WindowsTargetPlatformVersion>": "<WindowsTargetPlatformVersion>$(WindowsSDKVersion)</WindowsTargetPlatformVersion>",  # noqa: E501
             }
         },
         "build": [
             cmd_rmdir("Lib"),
-            cmd_rmdir(r"Projects\VC2017\Release"),
-            cmd_msbuild(r"Projects\VC2017\lcms2.sln", "Release", "Clean"),
+            cmd_rmdir(r"Projects\VC2019\Release"),
+            cmd_msbuild(r"Projects\VC2019\lcms2.sln", "Release", "Clean"),
             cmd_msbuild(
-                r"Projects\VC2017\lcms2.sln", "Release", "lcms2_static:Rebuild"
+                r"Projects\VC2019\lcms2.sln", "Release", "lcms2_static:Rebuild"
             ),
             cmd_xcopy("include", "{inc_dir}"),
         ],
@@ -490,7 +492,10 @@ def build_pillow():
     python_dir = os.environ.get("PYTHON")
     python_exe = os.environ.get("EXECUTABLE", "python.exe")
     architecture = os.environ.get(
-        "ARCHITECTURE", "x86" if struct.calcsize("P") == 4 else "x64"
+        "ARCHITECTURE",
+        "ARM64"
+        if platform.machine() == "ARM64"
+        else ("x86" if struct.calcsize("P") == 4 else "x64"),
     )
     build_dir = os.environ.get("PILLOW_BUILD", os.path.join(winbuild_dir, "build"))
     sources_dir = ""