Index: Doc/library/functions.rst
===================================================================
--- Doc/library/functions.rst	(revision 88501)
+++ Doc/library/functions.rst	(working copy)
@@ -97,8 +97,8 @@
      *errors*) parameters; :func:`bytearray` then converts the string to
      bytes using :meth:`str.encode`.
 
-   * If it is an *integer*, the array will have that size and will be
-     initialized with null bytes.
+   * If it is a non-negative *integer*, the array will have that size and will
+     be initialized with null bytes.
 
    * If it is an object conforming to the *buffer* interface, a read-only buffer
      of the object will be used to initialize the bytes array.
Index: Objects/bytearrayobject.c
===================================================================
--- Objects/bytearrayobject.c	(revision 88501)
+++ Objects/bytearrayobject.c	(working copy)
@@ -2790,12 +2790,16 @@
 };
 
 PyDoc_STRVAR(bytearray_doc,
-"bytearray(iterable_of_ints) -> bytearray\n\
+"bytearray() -> empty bytearray == bytearray(b'')\n\
+bytearray(count) -> bytearray with count null bytes\n\
+bytearray(iterable_of_ints) -> bytearray\n\
 bytearray(string, encoding[, errors]) -> bytearray\n\
 bytearray(bytes_or_bytearray) -> mutable copy of bytes_or_bytearray\n\
 bytearray(memory_view) -> bytearray\n\
 \n\
 Construct an mutable bytearray object from:\n\
+  - nothing\n\
+  - a non-negative integer\n\
   - an iterable yielding integers in range(256)\n\
   - a text string encoded using the specified encoding\n\
   - a bytes or a bytearray object\n\
Index: Objects/bytesobject.c
===================================================================
--- Objects/bytesobject.c	(revision 88501)
+++ Objects/bytesobject.c	(working copy)
@@ -2723,12 +2723,16 @@
 }
 
 PyDoc_STRVAR(bytes_doc,
-"bytes(iterable_of_ints) -> bytes\n\
+"bytes() -> empty bytes == b''\n\
+bytes(count) -> array of count null bytes == b'\x00'*count\n\
+bytes(iterable_of_ints) -> bytes\n\
 bytes(string, encoding[, errors]) -> bytes\n\
 bytes(bytes_or_buffer) -> immutable copy of bytes_or_buffer\n\
 bytes(memory_view) -> bytes\n\
 \n\
 Construct an immutable array of bytes from:\n\
+  - nothing\n\
+  - a non-negative integer\n\
   - an iterable yielding integers in range(256)\n\
   - a text string encoded using the specified encoding\n\
   - a bytes or a buffer object\n\