diff --git a/.github/workflows/windows.yml b/.github/workflows/windows.yml
index ef9e1f62..3277b9f3 100644
--- a/.github/workflows/windows.yml
+++ b/.github/workflows/windows.yml
@@ -50,6 +50,7 @@ jobs:
         vcvars:
           - 'vcvars32.bat'
           - 'vcvars64.bat'
+          - 'vcvarsamd64_arm64.bat'
         options:
           - 'pgo'
 
diff --git a/cpython-windows/build.py b/cpython-windows/build.py
index b3d61272..0f4bd6b6 100644
--- a/cpython-windows/build.py
+++ b/cpython-windows/build.py
@@ -438,6 +438,8 @@ def hack_props(
         suffix = b"-x64"
     elif arch == "win32":
         suffix = b""
+    elif arch == "arm64":
+        suffix = b"arm64"
     else:
         raise Exception("unhandled architecture: %s" % arch)
 
@@ -917,9 +919,11 @@ def build_openssl_for_arch(
     elif arch == "amd64":
         configure = "VC-WIN64A"
         prefix = "64"
+    elif arch == "arm64":
+        configure = "VC-WIN64-ARM"
+        prefix = "arm64"  # TODO check it ???
     else:
-        print("invalid architecture: %s" % arch)
-        sys.exit(1)
+        raise Exception("unhandled architecture: %s" % arch)
 
     # The official CPython OpenSSL builds hack ms/uplink.c to change the
     # ``GetModuleHandle(NULL)`` invocation to load things from _ssl.pyd
@@ -988,6 +992,7 @@ def build_openssl(
 
         root_32 = td / "x86"
         root_64 = td / "x64"
+        root_arm64 = td / "arm64"
 
         if arch == "x86":
             root_32.mkdir()
@@ -1011,13 +1016,28 @@ def build_openssl(
                 root_64,
                 jom_archive=jom_archive,
             )
+        elif arch == "arm64":
+            root_64.mkdir()
+            build_openssl_for_arch(
+                perl_path,
+                "arm64",
+                openssl_archive,
+                nasm_archive,
+                root_arm64,
+                profile,
+                jom_archive=jom_archive,
+            )
         else:
-            raise ValueError("unhandled arch: %s" % arch)
+            raise Exception("unhandled architecture: %s" % arch)
 
         install = td / "out"
 
         if arch == "x86":
             shutil.copytree(root_32 / "install" / "32", install / "openssl" / "win32")
+        elif arch == "arm64":
+            shutil.copytree(
+                root_arm64 / "install" / "arm64", install / "openssl" / "arm64"
+            )
         else:
             shutil.copytree(root_64 / "install" / "64", install / "openssl" / "amd64")
 
@@ -1088,9 +1108,14 @@ def build_libffi(
         if arch == "x86":
             args.append("-x86")
             artifacts_path = ffi_source_path / "i686-pc-cygwin"
-        else:
+        elif arch == "arm64":
+            args.append("-arm64")
+            artifacts_path = ffi_source_path / "aarch64-w64-cygwin"
+        elif arch == "amd64":
             args.append("-x64")
             artifacts_path = ffi_source_path / "x86_64-w64-cygwin"
+        else:
+            raise Exception("unhandled architecture: %s" % arch)
 
         subprocess.run(args, env=env, check=True)
 
@@ -1460,8 +1485,11 @@ def build_cpython(
     elif arch == "x86":
         build_platform = "win32"
         build_directory = "win32"
+    elif arch == "arm64":
+        build_platform = "arm64"
+        build_directory = "arm64"
     else:
-        raise ValueError("unhandled arch: %s" % arch)
+        raise Exception("unhandled architecture: %s" % arch)
 
     with tempfile.TemporaryDirectory(prefix="python-build-") as td:
         td = pathlib.Path(td)
@@ -1491,7 +1519,7 @@ def build_cpython(
 
         # We need all the OpenSSL library files in the same directory to appease
         # install rules.
-        openssl_arch = {"amd64": "amd64", "x86": "win32"}[arch]
+        openssl_arch = {"amd64": "amd64", "x86": "win32", "arm64": "arm64"}[arch]
         openssl_root = td / "openssl" / openssl_arch
         openssl_bin_path = openssl_root / "bin"
         openssl_lib_path = openssl_root / "lib"
@@ -1930,9 +1958,14 @@ def main() -> None:
         if os.environ.get("Platform") == "x86":
             target_triple = "i686-pc-windows-msvc"
             arch = "x86"
-        else:
+        elif os.environ.get("Platform") == "arm64":
+            target_triple = "aarch64-pc-windows-msvc"
+            arch = "arm64"
+        elif os.environ.get("Platform") == "x64":
             target_triple = "x86_64-pc-windows-msvc"
             arch = "amd64"
+        else:
+            raise Exception("unhandled architecture: %s" % os.environ.get("Platform"))
 
         # TODO need better dependency checking.