diff --git a/Doc/library/functions.rst b/Doc/library/functions.rst
index 43c47c1da9434c..caf7e1cacba868 100644
--- a/Doc/library/functions.rst
+++ b/Doc/library/functions.rst
@@ -134,9 +134,9 @@ are always available.  They are listed here in alphabetical order.
    This function drops you into the debugger at the call site.  Specifically,
    it calls :func:`sys.breakpointhook`, passing ``args`` and ``kws`` straight
    through.  By default, ``sys.breakpointhook()`` calls
-   :func:`pdb.set_trace()` expecting no arguments.  In this case, it is
-   purely a convenience function so you don't have to explicitly import
-   :mod:`pdb` or type as much code to enter the debugger.  However,
+   :func:`pdb.set_trace()` expecting an optional keyword argument `header`.  In
+   this case, it is purely a convenience function so you don't have to explicitly
+   import :mod:`pdb` or type as much code to enter the debugger.  However,
    :func:`sys.breakpointhook` can be set to some other function and
    :func:`breakpoint` will automatically call that, allowing you to drop into
    the debugger of choice.
diff --git a/Doc/library/sys.rst b/Doc/library/sys.rst
index d201d7061f9801..ee2e9634d3a47d 100644
--- a/Doc/library/sys.rst
+++ b/Doc/library/sys.rst
@@ -189,10 +189,10 @@ always available.
    function so that you can choose which debugger gets used.
 
    The signature of this function is dependent on what it calls.  For example,
-   the default binding (e.g. ``pdb.set_trace()``) expects no arguments, but
-   you might bind it to a function that expects additional arguments
-   (positional and/or keyword).  The built-in ``breakpoint()`` function passes
-   its ``*args`` and ``**kws`` straight through.  Whatever
+   the default binding (e.g. ``pdb.set_trace()``) expects only an optional keyword
+   argument `header`, but you might bind it to a function that expects additional
+   arguments (positional and/or keyword).  The built-in ``breakpoint()`` function
+   passes its ``*args`` and ``**kws`` straight through.  Whatever
    ``breakpointhooks()`` returns is returned from ``breakpoint()``.
 
    The default implementation first consults the environment variable