Add versionadded for sys.flags.hash_randomization variable
diff --git a/Doc/library/sys.rst b/Doc/library/sys.rst
index 2cf3267..691b30c 100644
--- a/Doc/library/sys.rst
+++ b/Doc/library/sys.rst
@@ -1,4 +1,3 @@
-
 :mod:`sys` --- System-specific parameters and functions
 =======================================================
 
@@ -291,6 +290,8 @@
 
    .. versionadded:: 2.6
 
+   .. versionadded:: 2.7.3
+      The ``hash_randomization`` attribute.
 
 .. data:: float_info