diff --git a/Lib/distutils/command/bdist_wininst.py b/Lib/distutils/command/bdist_wininst.py

index fde5675..15434c3 100644

--- a/Lib/distutils/command/bdist_wininst.py

+++ b/Lib/distutils/command/bdist_wininst.py

@@ -55,6 +55,9 @@ class bdist_wininst(Command):

     boolean_options = ['keep-temp', 'no-target-compile', 'no-target-optimize',

                        'skip-build']

+    # bpo-10945: bdist_wininst requires mbcs encoding only available on Windows

+    _unsupported = (sys.platform != "win32")

+

     def initialize_options(self):

         self.bdist_dir = None

         self.plat_name = None