diff --git a/lisp/play/gomoku.el b/lisp/play/gomoku.el
index d360b1d8a4b..3e61c6c4cf7 100644
--- a/lisp/play/gomoku.el
+++ b/lisp/play/gomoku.el
@@ -167,6 +167,9 @@ One useful value to include is `turn-on-font-lock' to highlight the pieces."
 (put 'gomoku-mode 'front-sticky
      (put 'gomoku-mode 'rear-nonsticky '(intangible)))
 (put 'gomoku-mode 'intangible 1)
+;; This one is for when they set view-read-only to t: Gomoku cannot
+;; allow View Mode to be activated in its buffer.
+(put 'gomoku-mode 'mode-class 'special)
 
 (defun gomoku-mode ()
   "Major mode for playing Gomoku against Emacs.