diff -r 22cfc057a1f1 Modules/_io/fileio.c
--- a/Modules/_io/fileio.c	Mon Jun 23 20:16:06 2014 -0700
+++ b/Modules/_io/fileio.c	Tue Jun 24 22:55:33 2014 +0800
@@ -1124,7 +1124,8 @@
 "This is needed for lower-level file interfaces, such the fcntl module.");
 
 PyDoc_STRVAR(seek_doc,
-"seek(offset: int[, whence: int]) -> None.  Move to new file position.\n"
+"seek(offset: int[, whence: int]) -> int.  Move to new file position\n"
+"and returns the file position."
 "\n"
 "Argument offset is a byte count.  Optional argument whence defaults to\n"
 "0 (offset from start of file, offset should be >= 0); other values are 1\n"
@@ -1136,7 +1137,8 @@
 
 #ifdef HAVE_FTRUNCATE
 PyDoc_STRVAR(truncate_doc,
-"truncate([size: int]) -> None.  Truncate the file to at most size bytes.\n"
+"truncate([size: int]) -> int.  Truncate the file to at most size bytes and\n"
+"returns the truncated size."
 "\n"
 "Size defaults to the current file position, as returned by tell()."
 "The current file position is changed to the value of size.");