#13530: port to 2.7 branch (document what os.lseek returns).
diff --git a/Doc/library/os.rst b/Doc/library/os.rst
index 679cedb..fe03096 100644
--- a/Doc/library/os.rst
+++ b/Doc/library/os.rst
@@ -744,7 +744,7 @@
by *how*: :const:`SEEK_SET` or ``0`` to set the position relative to the
beginning of the file; :const:`SEEK_CUR` or ``1`` to set it relative to the
current position; :const:`SEEK_END` or ``2`` to set it relative to the end of
- the file.
+ the file. Return the new cursor position in bytes, starting from the beginning.
Availability: Unix, Windows.