diff --git a/source/UI/js/Form/Checkbox.js b/source/UI/js/Form/Checkbox.js
index 89cb1d13..754d9f79 100644
--- a/source/UI/js/Form/Checkbox.js
+++ b/source/UI/js/Form/Checkbox.js
@@ -108,7 +108,7 @@ Ox.Checkbox = function(options, self) {
             type: 'image',
             value: self.options.indeterminate ? 'minus'
                 : self.options.value ? 'check' : 'none',
-            values: self.options.indeterminate ? null : ['none', 'check']
+            values: self.options.indeterminate ? [] : ['none', 'check']
         })
         .addClass('OxCheckbox')
         .bindEvent({