============================================================
 Create pseudo-terminal if one isn't passed in

  This may help us drop the nash depedency for
pty handling.

diff --git a/src/libply/ply-terminal-session.c b/src/libply/ply-terminal-session.c
--- a/src/libply/ply-terminal-session.c
+++ b/src/libply/ply-terminal-session.c
@@ -309,12 +309,24 @@ ply_terminal_session_attach (ply_terminal_session_t               *session,
   assert (session->loop != NULL);
   assert (!session->is_running);
   assert (session->done_handler == NULL);
-  assert (ptmx >= 0);
 
   should_redirect_console = 
     (flags & PLY_TERMINAL_SESSION_FLAGS_REDIRECT_CONSOLE) != 0;
 
-  ply_terminal_set_fd(session->terminal, ptmx);
+  if (ptmx >= 0)
+    {
+      ply_trace ("ptmx passed in, using it");
+      ply_terminal_set_fd(session->terminal, ptmx);
+    }
+  else
+    {
+      ply_trace ("ptmx not passed in, creating one");
+      if (!ply_terminal_create_device (session->terminal))
+        {
+          ply_trace ("could not create pseudo-terminal: %m");
+          return false;
+        }
+    }
 
   if (should_redirect_console)
     ply_trace ("redirecting system console to terminal device");
diff --git a/src/main.c b/src/main.c
--- a/src/main.c
+++ b/src/main.c
@@ -838,12 +838,6 @@ main (int    argc,
         }
     }
 
-  if ((attach_to_session && argc != 3) || (attach_to_session && state.ptmx == -1))
-    {
-      ply_error ("%s [--attach-to-session <pty_master_fd>]", argv[0]);
-      return EX_USAGE;
-    }
-
   if (geteuid () != 0)
     {
       ply_error ("plymouthd must be run as root user");