diff --git a/docs/cmd.rst b/docs/cmd.rst
index 2a5154e..6bf85fb 100644
--- a/docs/cmd.rst
+++ b/docs/cmd.rst
@@ -28,3 +28,18 @@ Cmd
     >>> from pydu.cmd import cmdline_argv
     >>> cmdline_argv()
     ['/Applications/PyCharm.app/Contents/helpers/pydev/pydevconsole.py', '61253', '61254']
+
+
+.. py:function:: pydu.cmd.chcp()
+
+    Context manager which sets the active code page number.
+    It could also be used as function.
+
+    >>> from pydu.cmd import chcp
+    >>> chcp(437)
+    <ctive code page number: 437>
+    >>> with chcp(437):
+    ...     pass
+    >>>
+
+    .. note:: ``chcp`` can only be used on ``Windows`` system.