diff --git a/framework/helpers/BaseHtml.php b/framework/helpers/BaseHtml.php
index 9e1d74cc89..ce1e54e2f9 100644
--- a/framework/helpers/BaseHtml.php
+++ b/framework/helpers/BaseHtml.php
@@ -1276,7 +1276,7 @@ class BaseHtml
$name = isset($options['name']) ? $options['name'] : static::getInputName($model, $attribute);
$selection = static::getAttributeValue($model, $attribute);
if (!array_key_exists('unselect', $options)) {
- $options['unselect'] = '0';
+ $options['unselect'] = '';
}
if (!array_key_exists('id', $options)) {
$options['id'] = static::getInputId($model, $attribute);