diff --git a/src/Renderer/Html/SideBySide.php b/src/Renderer/Html/SideBySide.php
index 170112e..5015521 100644
--- a/src/Renderer/Html/SideBySide.php
+++ b/src/Renderer/Html/SideBySide.php
@@ -49,13 +49,13 @@ final class SideBySide extends AbstractHtml
             return '';
         }
 
-        $colspan = $this->options['lineNumbers'] ? ' colspan="2"' : '';
-
         return
             '<thead>' .
                 '<tr>' .
-                    '<th' . $colspan . '>' . $this->_('old_version') . '</th>' .
-                    '<th' . $colspan . '>' . $this->_('new_version') . '</th>' .
+                    '<th>' . $this->_('old_version') . '</th>' .
+                    ($this->options['lineNumbers'] ? '<th></th>' : '') .
+                    '<th>' . $this->_('new_version') . '</th>' .
+                    ($this->options['lineNumbers'] ? '<th></th>' : '') .
                 '</tr>' .
             '</thead>';
     }