diff --git a/doc/emacs/misc.texi b/doc/emacs/misc.texi
index 737c871d3fb..1367f26acff 100644
--- a/doc/emacs/misc.texi
+++ b/doc/emacs/misc.texi
@@ -2025,7 +2025,7 @@ all server buffers are finished.  You can take as long as you like to
 edit the server buffers within Emacs, and they are @emph{not} killed
 when you type @kbd{C-x #} in them.
 
-@item --parent-id @var{id}
+@item --parent-id=@var{id}
 Open an @command{emacsclient} frame as a client frame in the parent X
 window with id @var{id}, via the XEmbed protocol.  Currently, this
 option is mainly useful for developers.