diff --git a/hgext/phabricator.py b/hgext/phabricator.py
--- a/hgext/phabricator.py
+++ b/hgext/phabricator.py
@@ -441,7 +441,7 @@
                 )
                 unfi.ui.warn(
                     _(
-                        b'D%s: local tag removed - does not match '
+                        b'D%d: local tag removed - does not match '
                         b'Differential history\n'
                     )
                     % drev