diff --git a/mercurial/localrepo.py b/mercurial/localrepo.py
--- a/mercurial/localrepo.py
+++ b/mercurial/localrepo.py
@@ -1870,8 +1870,8 @@ class localrepository(object):
                         # then, save the iteration
                         if self.obsstore:
                             # this message are here for 80 char limit reason
-                            mso = _("push includes an obsolete changeset: %s!")
-                            msu = _("push includes an unstable changeset: %s!")
+                            mso = _("push includes obsolete changeset: %s!")
+                            msu = _("push includes unstable changeset: %s!")
                             # If we are to push if there is at least one
                             # obsolete or unstable changeset in missing, at
                             # least one of the missinghead will be obsolete or
diff --git a/tests/test-obsolete.t b/tests/test-obsolete.t
--- a/tests/test-obsolete.t
+++ b/tests/test-obsolete.t
@@ -453,7 +453,7 @@ refuse to push obsolete changeset
   $ hg push ../tmpc/ -r 'desc("original_d")'
   pushing to ../tmpc/
   searching for changes
-  abort: push includes an obsolete changeset: 94b33453f93b!
+  abort: push includes obsolete changeset: 94b33453f93b!
   [255]
 
 refuse to push unstable changeset
@@ -461,7 +461,7 @@ refuse to push unstable changeset
   $ hg push ../tmpc/
   pushing to ../tmpc/
   searching for changes
-  abort: push includes an unstable changeset: cda648ca50f5!
+  abort: push includes unstable changeset: cda648ca50f5!
   [255]
 
 Test that extinct changeset are properly detected