diff --git a/source/Ox/js/Type.js b/source/Ox/js/Type.js
index 1bc09f73..4c7b7737 100644
--- a/source/Ox/js/Type.js
+++ b/source/Ox/js/Type.js
@@ -248,7 +248,7 @@ Ox.isInvalidDate <f> Tests if a value is an invalid date
     > Ox.isInvalidDate(new Date('foo'))
     true
 */
-Ox.isValidDate = function(value) {
+Ox.isInvalidDate = function(value) {
     return Ox.isDate(value) && Ox.isNaN(value.getTime());
 };