diff --git a/mercurial/scmutil.py b/mercurial/scmutil.py
--- a/mercurial/scmutil.py
+++ b/mercurial/scmutil.py
@@ -503,7 +503,7 @@
             rev = repo.changelog.rev(node)
             return repo[rev]
 
-        return repo[symbol]
+        raise error.RepoLookupError(_("unknown revision '%s'") % symbol)
 
     except error.WdirUnsupported:
         return repo[None]
diff --git a/tests/test-pull.t b/tests/test-pull.t
--- a/tests/test-pull.t
+++ b/tests/test-pull.t
@@ -72,7 +72,7 @@
   [255]
   $ hg pull -r 'xxxxxxxxxxxxxxxxxx y'
   pulling from http://foo@localhost:$HGPORT/
-  abort: unknown revision '7878787878787878787878787878787878782079'!
+  abort: unknown revision 'xxxxxxxxxxxxxxxxxx y'!
   [255]
 
 Issue622: hg init && hg pull -u URL doesn't checkout default branch