diff --git a/wv-window.rkt b/wv-window.rkt
index e83f601..13f9370 100644
--- a/wv-window.rkt
+++ b/wv-window.rkt
@@ -108,9 +108,9 @@
                                              id)))
               (set! type (if (eq? js-type #f)
                              #f
-                             (if (= js-type -1)
-                                 'unknown
-                                 (string->symbol (string-downcase js-type))))))
+                             (if (string? js-type)
+                                 (string->symbol (string-downcase js-type))
+                                 'unknown)))
             )
           (let ((cl (cond
                       ((eq? type 'text) wv-input/text%)