diff --git a/h5p.classes.php b/h5p.classes.php
index c281ab7..afcb817 100644
--- a/h5p.classes.php
+++ b/h5p.classes.php
@@ -3333,7 +3333,7 @@ class H5PContentValidator {
   public $h5pF;
   public $h5pC;
   private $typeMap, $libraries, $dependencies, $nextWeight;
-  private static $allowed_styleable_tags = array('span', 'p', 'div','h1','h2','h3', 'table', 'td');
+  private static $allowed_styleable_tags = array('span', 'p', 'div','h1','h2','h3', 'table', 'th', 'td');
 
   /**
    * Constructor for the H5PContentValidator