diff --git a/hgext3rd/pushrebase.py b/hgext3rd/pushrebase.py
--- a/hgext3rd/pushrebase.py
+++ b/hgext3rd/pushrebase.py
@@ -196,8 +196,16 @@
     if not repo.revs(revset):
         raise error.Abort(_('nothing to rebase'))
 
-    if repo.revs('%r and public()', revset):
-        raise error.Abort(_('cannot rebase public changesets'))
+    revs = repo.revs('%r and public()', revset)
+    if revs:
+        nodes = []
+        for count, rev in enumerate(revs):
+            if count >= 3:
+                nodes.append('...')
+                break
+            nodes.append(str(repo[rev]))
+        revstring = ', '.join(nodes)
+        raise error.Abort(_('cannot rebase public changesets: %s') % revstring)
 
     if repo.revs('%r and obsolete()', revset):
         raise error.Abort(_('cannot rebase obsolete changesets'))
diff --git a/tests/test-pushrebase.t b/tests/test-pushrebase.t
--- a/tests/test-pushrebase.t
+++ b/tests/test-pushrebase.t
@@ -937,3 +937,28 @@
   (pull and rebase your changes locally, then try again)
   [255]
 
+Push an already-public changeset and confirm it is rejected
+
+  $ hg update -q '.^'
+  $ echo 2 > C
+  $ hg commit -m C -A C
+  created new head
+  $ hg phase -r. --public
+  $ hg push -r . --to default
+  pushing to $TESTTMP/server2 (glob)
+  searching for changes
+  abort: cannot rebase public changesets: 3850a85c4706
+  [255]
+
+  $ echo 3 >> C
+  $ hg commit -m C2
+  $ echo 4 >> C
+  $ hg commit -m C3
+  $ echo 5 >> C
+  $ hg commit -m C4
+  $ hg phase -r. --public
+  $ hg push -r . --to default
+  pushing to $TESTTMP/server2 (glob)
+  searching for changes
+  abort: cannot rebase public changesets: 3850a85c4706, 50b1220b7c4e, de211a1843b7, ...
+  [255]