diff --git a/scripts/md2html/md2html.js b/scripts/md2html/md2html.js
index ef95f67761..fd3ec78f69 100644
--- a/scripts/md2html/md2html.js
+++ b/scripts/md2html/md2html.js
@@ -13,6 +13,41 @@ const path = require('path');
 const url = require('url');
 
 const hljs = require('highlight.js');
+hljs.registerLanguage('uritemplate', function() {
+    return {
+      case_insensitive: true,
+      contains: [
+          {
+              scope: "attr", 
+              match: /(?<=[{,])[^,}\n\r]+/,
+          }
+      ],
+    }
+  });
+hljs.registerLanguage('uri', function() {
+    return {
+      case_insensitive: true,
+      classNameAliases: {
+          pathsegment: "attr",
+          option: "attr",
+          value: "literal"
+      },
+      contains: [
+          {
+              scope: "pathsegment", 
+              match: /(?<=[/])[^/?#\n\r]+/,
+          },
+          {
+              scope: "option", 
+              match: /(?<=[?&#])[^=?&#\n\r]+/,
+          },
+          {
+              scope: "value",
+              match: /(?<=\=)[^?&#\n\r]+/,
+          }
+      ],
+    }
+  });
 const cheerio = require('cheerio');
 
 let argv = require('yargs')
@@ -36,7 +71,8 @@ const md = require('markdown-it')({
       '</code></pre>';
     }
 
-    return '<pre class="highlight '+lang+'" tabindex="0"><code>' + md.utils.escapeHtml(str) + '</code></pre>';
+    if (lang) console.warn('highlight.js does not support language',lang);
+    return '<pre class="nohighlight" tabindex="0"><code>' + md.utils.escapeHtml(str) + '</code></pre>';
   }
 });
 
diff --git a/tests/md2html/fixtures/basic-new.html b/tests/md2html/fixtures/basic-new.html
index f9fecd4a12..c1b911743b 100644
--- a/tests/md2html/fixtures/basic-new.html
+++ b/tests/md2html/fixtures/basic-new.html
@@ -24,7 +24,13 @@
 </code></pre>
 <pre class="nohighlight" tabindex="0"><code>text/plain
 </code></pre>
-<pre class="highlight " tabindex="0"><code>no language
+<pre class="nohighlight" tabindex="0"><code>no language
+</code></pre>
+<pre class="nohighlight" tabindex="0"><code>unknown language
+</code></pre>
+<pre class="nohighlight" tabindex="0"><code>https://<span class="hljs-attr">foo.com</span>/<span class="hljs-attr">bar</span>?<span class="hljs-attr">baz</span>=<span class="hljs-literal">qux</span>&amp;<span class="hljs-attr">fred</span>=<span class="hljs-literal">waldo</span>#<span class="hljs-attr">fragment</span>
+</code></pre>
+<pre class="nohighlight" tabindex="0"><code>https://foo.com/bar{<span class="hljs-attr">?baz*</span>,<span class="hljs-attr">qux</span>}
 </code></pre>
 </section></section><section class="appendix"><h1>Appendix A: Revision History</h1>
 <table>
diff --git a/tests/md2html/fixtures/basic-new.md b/tests/md2html/fixtures/basic-new.md
index 8d0c1e6efd..2119776f54 100644
--- a/tests/md2html/fixtures/basic-new.md
+++ b/tests/md2html/fixtures/basic-new.md
@@ -50,6 +50,18 @@ text/plain
 no language
 ```
 
+```unknown
+unknown language
+```
+
+```uri
+https://foo.com/bar?baz=qux&fred=waldo#fragment
+```
+
+```uritemplate
+https://foo.com/bar{?baz*,qux}
+```
+
 ## Appendix A: Revision History
 
 Version | Date