diff --git a/Parsedown.php b/Parsedown.php
index b8adb05..ae0cbde 100644
--- a/Parsedown.php
+++ b/Parsedown.php
@@ -17,7 +17,7 @@ class Parsedown
 {
     # ~
 
-    const version = '1.8.0-beta-5';
+    const version = '1.8.0-beta-7';
 
     # ~
 
@@ -470,7 +470,21 @@ class Parsedown
 
         if ($infostring !== '')
         {
-            $Element['attributes'] = array('class' => "language-$infostring");
+            /**
+             * https://www.w3.org/TR/2011/WD-html5-20110525/elements.html#classes
+             * Every HTML element may have a class attribute specified.
+             * The attribute, if specified, must have a value that is a set
+             * of space-separated tokens representing the various classes
+             * that the element belongs to.
+             * [...]
+             * The space characters, for the purposes of this specification,
+             * are U+0020 SPACE, U+0009 CHARACTER TABULATION (tab),
+             * U+000A LINE FEED (LF), U+000C FORM FEED (FF), and
+             * U+000D CARRIAGE RETURN (CR).
+             */
+            $language = substr($infostring, 0, strcspn($infostring, " \t\n\f\r"));
+
+            $Element['attributes'] = array('class' => "language-$language");
         }
 
         $Block = array(