diff --git a/_inc/lib/markdown/extra.php b/_inc/lib/markdown/extra.php
index 1f411dad00238..6fd39949a8e72 100644
--- a/_inc/lib/markdown/extra.php
+++ b/_inc/lib/markdown/extra.php
@@ -103,7 +103,6 @@ function __construct() {
 	#
 	# Constructor function. Initialize appropriate member variables.
 	#
-		$this->_initDetab();
 		$this->prepareItalicsAndBold();
 
 		$this->nested_brackets_re =
@@ -1481,10 +1480,6 @@ function outdent($text) {
 	}
 
 
-	# String length function for detab. `_initDetab` will create a function to
-	# hanlde UTF-8 if the default function does not exist.
-	public $utf8_strlen = 'mb_strlen';
-
 	function detab($text) {
 	#
 	# Replace tabs with the appropriate amount of space.
@@ -1500,7 +1495,6 @@ function detab($text) {
 	}
 	function _detab_callback($matches) {
 		$line = $matches[0];
-		$strlen = $this->utf8_strlen; # strlen function for UTF-8.
 
 		# Split in blocks.
 		$blocks = explode("\t", $line);
@@ -1510,24 +1504,11 @@ function _detab_callback($matches) {
 		foreach ($blocks as $block) {
 			# Calculate amount of space, insert spaces, insert block.
 			$amount = $this->tab_width -
-				$strlen($line, 'UTF-8') % $this->tab_width;
+				mb_strlen($line, 'UTF-8') % $this->tab_width;
 			$line .= str_repeat(" ", $amount) . $block;
 		}
 		return $line;
 	}
-	function _initDetab() {
-	#
-	# Check for the availability of the function in the `utf8_strlen` property
-	# (initially `mb_strlen`). If the function is not available, create a
-	# function that will loosely count the number of UTF-8 characters with a
-	# regular expression.
-	#
-		if (function_exists($this->utf8_strlen)) return;
-		$this->utf8_strlen = create_function('$text', 'return preg_match_all(
-			"/[\\\\x00-\\\\xBF]|[\\\\xC0-\\\\xFF][\\\\x80-\\\\xBF]*/",
-			$text, $m);');
-	}
-
 
 	function unhash($text) {
 	#
@@ -2157,8 +2138,7 @@ function _hashHTMLBlocks_inHTML($text, $hash_method, $md_attr) {
 
 					# Calculate indent before tag.
 					if (preg_match('/(?:^|\n)( *?)(?! ).*?$/', $block_text, $matches)) {
-						$strlen = $this->utf8_strlen;
-						$indent = $strlen($matches[1], 'UTF-8');
+						$indent = mb_strlen($matches[1], 'UTF-8');
 					} else {
 						$indent = 0;
 					}