diff --git a/contrib/all-revsets.txt b/contrib/all-revsets.txt
--- a/contrib/all-revsets.txt
+++ b/contrib/all-revsets.txt
@@ -138,3 +138,4 @@ secret()
 
 # test finding common ancestors
 heads(commonancestors(last(head(), 2)))
+heads(commonancestors(head()))
diff --git a/contrib/base-revsets.txt b/contrib/base-revsets.txt
--- a/contrib/base-revsets.txt
+++ b/contrib/base-revsets.txt
@@ -46,3 +46,4 @@ parents(20000)
 (20000::) - (20000)
 # The one below is used by rebase
 (children(ancestor(tip~5, tip)) and ::(tip~5))::
+heads(commonancestors(last(head(), 2)))