syntax highlighting - PrismJS horizontal line in language-docker -

i using prismjs code hightkighting. worked perfect until now. added docker , add docker file. rendering of code works, random horizontal line appears. cannot see in html?

screenshot

html output

<pre class=" language-docker">     <code class=" language-docker">         <span class="token comment" spellcheck="true">             # install stable node.js , related build tools</span>         <span class="token keyword">run</span>         curl          <span class="token punctuation">-</span>         sl https         <span class="token punctuation">:</span>         //git.io/n         <span class="token punctuation">-</span>         install          <span class="token punctuation">|</span>          bash          <span class="token punctuation">-</span>         s          <span class="token punctuation">-</span>         <span class="token punctuation">-</span>          <span class="token punctuation">-</span>         ny          <span class="token punctuation">-</span> \         &amp;&amp; ~/n/bin/n stable \         &amp;&amp; npm install <span class="token punctuation">-</span>g bower grunt gulp n \         &amp;&amp; rm <span class="token punctuation">-</span>rf ~/n     </code> </pre> 

any ideas?