diff --git a/Doc/distutils/builtdist.rst b/Doc/distutils/builtdist.rst
index f44d0d0..8c65d9d 100644
--- a/Doc/distutils/builtdist.rst
+++ b/Doc/distutils/builtdist.rst
@@ -315,8 +315,8 @@
 
 If you have a pure module distribution (only containing pure Python modules and
 packages), the resulting installer will be version independent and have a name
-like :file:`foo-1.0.win32.exe`.  These installers can even be created on Unix
-platforms or Mac OS X.
+like :file:`foo-1.0.win32.exe`. Note that creating ``wininst`` binary
+distributions in only supported on Windows systems.
 
 If you have a non-pure distribution, the extensions can only be created on a
 Windows platform, and will be Python version dependent. The installer filename
diff --git a/Lib/distutils/command/bdist_wininst.py b/Lib/distutils/command/bdist_wininst.py
index 3a61688..acaa184 100644
--- a/Lib/distutils/command/bdist_wininst.py
+++ b/Lib/distutils/command/bdist_wininst.py
@@ -55,6 +55,9 @@
     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
diff --git a/Misc/NEWS.d/next/Windows/2019-07-01-12-38-48.bpo-10945.s0YBHG.rst b/Misc/NEWS.d/next/Windows/2019-07-01-12-38-48.bpo-10945.s0YBHG.rst
new file mode 100644
index 0000000..d395765
--- /dev/null
+++ b/Misc/NEWS.d/next/Windows/2019-07-01-12-38-48.bpo-10945.s0YBHG.rst
@@ -0,0 +1,2 @@
+Officially drop support for creating bdist_wininst installers on non-Windows
+systems.