diff --git a/Doc/library/tempfile.rst b/Doc/library/tempfile.rst
index beb02a6c3a1..19e1e7faaf1 100644
--- a/Doc/library/tempfile.rst
+++ b/Doc/library/tempfile.rst
@@ -33,7 +33,7 @@ is recommended to use keyword arguments for clarity.
 
 The module defines the following user-callable items:
 
-.. function:: TemporaryFile(mode='w+b', buffering=None, encoding=None, newline=None, suffix='', prefix='tmp', dir=None)
+.. function:: TemporaryFile(mode='w+b', buffering=None, encoding=None, newline=None, suffix=None, prefix=None, dir=None)
 
    Return a :term:`file-like object` that can be used as a temporary storage area.
    The file is created securely, using the same rules as :func:`mkstemp`. It will be destroyed as soon
@@ -54,8 +54,8 @@ The module defines the following user-callable items:
    stored.  *buffering*, *encoding* and *newline* are interpreted as for
    :func:`open`.
 
-   The *dir*, *prefix* and *suffix* parameters have the same meaning
-   as with :func:`mkstemp`.
+   The *dir*, *prefix* and *suffix* parameters have the same meaning and
+   defaults as with :func:`mkstemp`.
 
    The returned object is a true file object on POSIX platforms.  On other
    platforms, it is a file-like object whose :attr:`!file` attribute is the
@@ -69,7 +69,7 @@ The module defines the following user-callable items:
       The :py:data:`os.O_TMPFILE` flag is now used if available.
 
 
-.. function:: NamedTemporaryFile(mode='w+b', buffering=None, encoding=None, newline=None, suffix='', prefix='tmp', dir=None, delete=True)
+.. function:: NamedTemporaryFile(mode='w+b', buffering=None, encoding=None, newline=None, suffix=None, prefix=None, dir=None, delete=True)
 
    This function operates exactly as :func:`TemporaryFile` does, except that
    the file is guaranteed to have a visible name in the file system (on
@@ -84,7 +84,7 @@ The module defines the following user-callable items:
    be used in a :keyword:`with` statement, just like a normal file.
 
 
-.. function:: SpooledTemporaryFile(max_size=0, mode='w+b', buffering=None, encoding=None, newline=None, suffix='', prefix='tmp', dir=None)
+.. function:: SpooledTemporaryFile(max_size=0, mode='w+b', buffering=None, encoding=None, newline=None, suffix=None, prefix=None, dir=None)
 
    This function operates exactly as :func:`TemporaryFile` does, except that
    data is spooled in memory until the file size exceeds *max_size*, or
@@ -106,7 +106,7 @@ The module defines the following user-callable items:
       the truncate method now accepts a ``size`` argument.
 
 
-.. function:: TemporaryDirectory(suffix='', prefix='tmp', dir=None)
+.. function:: TemporaryDirectory(suffix=None, prefix=None, dir=None)
 
    This function securely creates a temporary directory using the same rules as :func:`mkdtemp`.
    The resulting object can be used as a context manager (see
@@ -138,15 +138,16 @@ The module defines the following user-callable items:
    Unlike :func:`TemporaryFile`, the user of :func:`mkstemp` is responsible
    for deleting the temporary file when done with it.
 
-   If *suffix* is specified, the file name will end with that suffix,
+   If *suffix* is not ``None``, the file name will end with that suffix,
    otherwise there will be no suffix.  :func:`mkstemp` does not put a dot
    between the file name and the suffix; if you need one, put it at the
    beginning of *suffix*.
 
-   If *prefix* is specified, the file name will begin with that prefix;
-   otherwise, a default prefix is used.
+   If *prefix* is not ``None``, the file name will begin with that prefix;
+   otherwise, a default prefix is used.  The default is the return value of
+   :func:`gettempprefix` or :func:`gettempprefixb`, as appropriate.
 
-   If *dir* is specified, the file will be created in that directory;
+   If *dir* is not ``None``, the file will be created in that directory;
    otherwise, a default directory is used.  The default directory is chosen
    from a platform-dependent list, but the user of the application can
    control the directory location by setting the *TMPDIR*, *TEMP* or *TMP*
@@ -154,16 +155,12 @@ The module defines the following user-callable items:
    filename will have any nice properties, such as not requiring quoting
    when passed to external commands via ``os.popen()``.
 
-   *suffix*, *prefix*, and *dir* must all contain the same type, if specified.
+   If any of *suffix*, *prefix*, and *dir* are not
+   ``None``, they must be the same type.
    If they are bytes, the returned name will be bytes instead of str.
    If you want to force a bytes return value with otherwise default behavior,
    pass ``suffix=b''``.
 
-   A *prefix* value of ``None`` means use the return value of
-   :func:`gettempprefix` or :func:`gettempprefixb` as appropriate.
-
-   A *suffix* value of ``None`` means use an appropriate empty value.
-
    If *text* is specified, it indicates whether to open the file in binary
    mode (the default) or text mode.  On some platforms, this makes no
    difference.
@@ -241,7 +238,7 @@ The module defines the following user-callable items:
 
 .. function:: gettempprefixb()
 
-   Same as :func:`gettempprefixb` but the return value is in bytes.
+   Same as :func:`gettempprefix` but the return value is in bytes.
 
    .. versionadded:: 3.5
 
@@ -314,8 +311,9 @@ other functions described above.
       Use :func:`mkstemp` instead.
 
    Return an absolute pathname of a file that did not exist at the time the
-   call is made.  The *prefix*, *suffix*, and *dir* arguments are the same
-   as for :func:`mkstemp`.
+   call is made.  The *prefix*, *suffix*, and *dir* arguments are similar
+   to those of :func:`mkstemp`, except that bytes file names, ``suffix=None``
+   and ``prefix=None`` are not supported.
 
    .. warning::
 
diff --git a/Lib/tempfile.py b/Lib/tempfile.py
index e87eb093356..d381a25dd19 100644
--- a/Lib/tempfile.py
+++ b/Lib/tempfile.py
@@ -307,22 +307,22 @@ def mkstemp(suffix=None, prefix=None, dir=None, text=False):
     file.  The return value is a pair (fd, name) where fd is the
     file descriptor returned by os.open, and name is the filename.
 
-    If 'suffix' is specified, the file name will end with that suffix,
+    If 'suffix' is not None, the file name will end with that suffix,
     otherwise there will be no suffix.
 
-    If 'prefix' is specified, the file name will begin with that prefix,
+    If 'prefix' is not None, the file name will begin with that prefix,
     otherwise a default prefix is used.
 
-    If 'dir' is specified, the file will be created in that directory,
+    If 'dir' is not None, the file will be created in that directory,
     otherwise a default directory is used.
 
     If 'text' is specified and true, the file is opened in text
     mode.  Else (the default) the file is opened in binary mode.  On
     some operating systems, this makes no difference.
 
-    suffix, prefix and dir must all contain the same type if specified.
-    If they are bytes, the returned name will be bytes; str otherwise.
-    A value of None will cause an appropriate default to be used.
+    If any of 'suffix', 'prefix' and 'dir' are not None, they must be the
+    same type.  If they are bytes, the returned name will be bytes; str
+    otherwise.
 
     The file is readable and writable only by the creating user ID.
     If the operating system uses permission bits to indicate whether a
@@ -385,8 +385,9 @@ def mktemp(suffix="", prefix=template, dir=None):
     """User-callable function to return a unique temporary file name.  The
     file is not created.
 
-    Arguments are as for mkstemp, except that the 'text' argument is
-    not accepted.
+    Arguments are similar to mkstemp, except that the 'text' argument is
+    not accepted, and suffix=None, prefix=None and bytes file names are not
+    supported.
 
     THIS FUNCTION IS UNSAFE AND SHOULD NOT BE USED.  The file name may
     refer to a file that did not exist at some point, but by the time