diff --git a/app/code/core/Mage/Captcha/Block/Captcha/Zend.php b/app/code/core/Mage/Captcha/Block/Captcha/Zend.php
index af00efddd72..d77bb138542 100644
--- a/app/code/core/Mage/Captcha/Block/Captcha/Zend.php
+++ b/app/code/core/Mage/Captcha/Block/Captcha/Zend.php
@@ -55,6 +55,14 @@ public function getRefreshUrl()
     protected function _toHtml()
     {
         if (Mage::helper('captcha')->isEnabled() && $this->getCaptchaModel()->isRequired()) {
+            if ($this->hasData('img_width')) {
+                $this->getCaptchaModel()->setWidth($this->getData('img_width'));
+            }
+
+            if ($this->hasData('img_height')) {
+                $this->getCaptchaModel()->setHeight($this->getData('img_height'));
+            }
+
             $this->getCaptchaModel()->generate();
             return parent::_toHtml();
         }