diff --git a/lisp/emacs-lisp/eieio-base.el b/lisp/emacs-lisp/eieio-base.el
index 0241f27395..a37cf7a1b3 100644
--- a/lisp/emacs-lisp/eieio-base.el
+++ b/lisp/emacs-lisp/eieio-base.el
@@ -349,7 +349,7 @@ eieio-persistent-validate/fix-slot-value
                        (seq-some
                         (lambda (elt)
                           (child-of-class-p (car proposed-value) elt))
-                        classtype))
+                        (if (consp classtype) classtype (list classtype))))
 		  (eieio-persistent-convert-list-to-object
 		   proposed-value))
 		 (t