diff --git a/mercurial/revset.py b/mercurial/revset.py
index 582080a4a812ac55ce6b4082ff183edd3c64258e_bWVyY3VyaWFsL3JldnNldC5weQ==..2851b24eecc483ce1546d63d155fa2e9250e3f44_bWVyY3VyaWFsL3JldnNldC5weQ== 100644
--- a/mercurial/revset.py
+++ b/mercurial/revset.py
@@ -247,7 +247,8 @@
 
 @predicate('ancestors(set)', safe=True)
 def ancestors(repo, subset, x):
-    """Changesets that are ancestors of a changeset in set.
+    """Changesets that are ancestors of changesets in set, including the
+    given changesets themselves.
     """
     return _ancestors(repo, subset, x)
 
@@ -592,7 +593,8 @@
 
 @predicate('descendants(set)', safe=True)
 def descendants(repo, subset, x):
-    """Changesets which are descendants of changesets in set.
+    """Changesets which are descendants of changesets in set, including the
+    given changesets themselves.
     """
     return _descendants(repo, subset, x)