diff --git a/types.lisp b/types.lisp
index 3797c89..1fb5a54 100644
--- a/types.lisp
+++ b/types.lisp
@@ -513,6 +513,9 @@ Functions\", by Irène Durand and Robert Strandh."
                                         (with-read-only-vars (,var)
                                           (with-vref ,type
                                             ,@body))))))))
+              ((or #+clasp t)
+               `(locally (declare (type (or ,@types) ,var))
+                  ,@body))
               (t
                `(with-type-declarations-trusted ()
                   (etypecase ,var