diff --git a/system/helpers/captcha_helper.php b/system/helpers/captcha_helper.php
index 5d023b2..8c2cfa4 100644
--- a/system/helpers/captcha_helper.php
+++ b/system/helpers/captcha_helper.php
@@ -71,6 +71,7 @@
 			'font_path'	=> '',
 			'expiration'	=> 7200,
 			'word_length'	=> 8,
+			'font_size' =>16,
 			'pool'		=> '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ',
 			'colors'	=> array(
 				'background'	=> array(255,255,255),
@@ -193,13 +194,13 @@
 		$use_font = ($font_path !== '' && file_exists($font_path) && function_exists('imagettftext'));
 		if ($use_font === FALSE)
 		{
-			$font_size = 5;
+			$font_size = $font_size>5?5:$font_size;
 			$x = mt_rand(0, $img_width / ($length / 3));
 			$y = 0;
 		}
 		else
 		{
-			$font_size = 16;
+			$font_size = $font_size>30?30:$font_size;
 			$x = mt_rand(0, $img_width / ($length / 1.5));
 			$y = $font_size + 2;
 		}