diff --git a/apps/advanced/frontend/views/site/contact.php b/apps/advanced/frontend/views/site/contact.php
index 17c4f79..9aa98e6 100644
--- a/apps/advanced/frontend/views/site/contact.php
+++ b/apps/advanced/frontend/views/site/contact.php
@@ -26,7 +26,6 @@ $this->params['breadcrumbs'][] = $this->title;
 				<?= $form->field($model, 'subject') ?>
 				<?= $form->field($model, 'body')->textArea(['rows' => 6]) ?>
 				<?= $form->field($model, 'verifyCode')->widget(Captcha::className(), [
-					'options' => ['class' => 'form-control'],
 					'template' => '<div class="row"><div class="col-lg-3">{image}</div><div class="col-lg-6">{input}</div></div>',
 				]) ?>
 				<div class="form-group">
diff --git a/apps/basic/views/site/contact.php b/apps/basic/views/site/contact.php
index d2e59af..ebd148e 100644
--- a/apps/basic/views/site/contact.php
+++ b/apps/basic/views/site/contact.php
@@ -34,7 +34,6 @@ $this->params['breadcrumbs'][] = $this->title;
 				<?= $form->field($model, 'subject') ?>
 				<?= $form->field($model, 'body')->textArea(['rows' => 6]) ?>
 				<?= $form->field($model, 'verifyCode')->widget(Captcha::className(), [
-					'options' => ['class' => 'form-control'],
 					'template' => '<div class="row"><div class="col-lg-3">{image}</div><div class="col-lg-6">{input}</div></div>',
 				]) ?>
 				<div class="form-group">
diff --git a/framework/CHANGELOG.md b/framework/CHANGELOG.md
index 6991525..747e59d 100644
--- a/framework/CHANGELOG.md
+++ b/framework/CHANGELOG.md
@@ -39,6 +39,7 @@ Yii Framework 2 Change Log
 - Enh: Support for file aliases in console command 'message' (omnilight)
 - Enh: Sort and Pagination can now create absolute URLs (cebe)
 - Chg #1610: `Html::activeCheckboxList()` and `Html::activeRadioList()` will submit an empty string if no checkbox/radio is selected (qiangxue)
+- Chg #1643: Added default value for `Captcha::options` (qiangxue)
 - Chg: Renamed `yii\jui\Widget::clientEventsMap` to `clientEventMap` (qiangxue)
 - Chg: Renamed `ActiveRecord::getPopulatedRelations()` to `getRelatedRecords()` (qiangxue)
 - Chg: Renamed `attributeName` and `className` to `targetAttribute` and `targetClass` for `UniqueValidator` and `ExistValidator` (qiangxue)
diff --git a/framework/yii/captcha/Captcha.php b/framework/yii/captcha/Captcha.php
index 18b8765..9e69b9e 100644
--- a/framework/yii/captcha/Captcha.php
+++ b/framework/yii/captcha/Captcha.php
@@ -48,6 +48,10 @@ class Captcha extends InputWidget
 	 * while `{input}` will be replaced with the text input tag.
 	 */
 	public $template = '{image} {input}';
+	/**
+	 * @var array the HTML attributes for the input tag.
+	 */
+	public $options = ['class' => 'form-control'];
 
 	/**
 	 * Initializes the widget.