diff --git a/mercurial/pycompat.py b/mercurial/pycompat.py
--- a/mercurial/pycompat.py
+++ b/mercurial/pycompat.py
@@ -99,7 +99,7 @@
         # Otherwise non-ASCII filenames in existing repositories would be
         # corrupted.
         # This must be set once prior to any fsencode/fsdecode calls.
-        sys._enablelegacywindowsfsencoding()
+        sys._enablelegacywindowsfsencoding()  # pytype: disable=module-attr
 
     fsencode = os.fsencode
     fsdecode = os.fsdecode
diff --git a/mercurial/scmwindows.py b/mercurial/scmwindows.py
--- a/mercurial/scmwindows.py
+++ b/mercurial/scmwindows.py
@@ -10,11 +10,12 @@
 )
 
 try:
-    import _winreg as winreg
+    import _winreg as winreg  # pytype: disable=import-error
 
     winreg.CloseKey
 except ImportError:
-    import winreg
+    # py2 only
+    import winreg  # pytype: disable=import-error
 
 # MS-DOS 'more' is the only pager available by default on Windows.
 fallbackpager = b'more'
diff --git a/mercurial/windows.py b/mercurial/windows.py
--- a/mercurial/windows.py
+++ b/mercurial/windows.py
@@ -26,11 +26,12 @@
 )
 
 try:
-    import _winreg as winreg
+    import _winreg as winreg  # pytype: disable=import-error
 
     winreg.CloseKey
 except ImportError:
-    import winreg
+    # py2 only
+    import winreg  # pytype: disable=import-error
 
 osutil = policy.importmod('osutil')
 
@@ -282,7 +283,7 @@
     # fileno(), usually set to -1.
     fno = getattr(fd, 'fileno', None)
     if fno is not None and fno() >= 0:
-        msvcrt.setmode(fno(), os.O_BINARY)
+        msvcrt.setmode(fno(), os.O_BINARY)  # pytype: disable=module-attr
 
 
 def pconvert(path):