diff --git a/syntaxhighlighter.php b/syntaxhighlighter.php
index 667a2b7..d0db9cb 100644
--- a/syntaxhighlighter.php
+++ b/syntaxhighlighter.php
@@ -500,6 +500,7 @@ public function enable_brushes_via_raw_html_parsing( $content ) {
 	 */
 	public function render_block( $attributes, $content ) {
 		$remaps = array(
+			'className'         => 'classname',
 			'lineNumbers'       => 'gutter',
 			'firstLineNumber'   => 'firstline',
 			'highlightLines'    => 'highlight',
@@ -1243,7 +1244,7 @@ function shortcode_callback( $atts, $code = '', $tag = false ) {
 
 			// Sanitize the "classname" parameter
 			if ( 'class-name' == $key )
-				$value = trim( preg_replace( '/[^a-zA-Z0-9 _-]/i', '', $value ) );
+				$value = "'" . trim( preg_replace( '/[^a-zA-Z0-9 _-]/i', '', $value ) ) . "'";
 
 			// Special sanitization for "pad-line-numbers"
 			if ( 'pad-line-numbers' == $key ) {