diff --git a/app/assets/javascripts/pretty-text/white-lister.js.es6 b/app/assets/javascripts/pretty-text/white-lister.js.es6
index 0841d9a1217..c293b18135e 100644
--- a/app/assets/javascripts/pretty-text/white-lister.js.es6
+++ b/app/assets/javascripts/pretty-text/white-lister.js.es6
@@ -114,6 +114,7 @@ whiteListFeature('default', [
   'aside.quote',
   'aside[data-*]',
   'b',
+  'big',
   'blockquote',
   'br',
   'code',
diff --git a/test/javascripts/lib/sanitizer-test.js.es6 b/test/javascripts/lib/sanitizer-test.js.es6
index bc67c5c3c27..dd3fd47323d 100644
--- a/test/javascripts/lib/sanitizer-test.js.es6
+++ b/test/javascripts/lib/sanitizer-test.js.es6
@@ -55,7 +55,7 @@ test("sanitize", function() {
   cooked(`1 + 1 is <del>3</del> <ins>2</ins>`, `<p>1 + 1 is <del>3</del> <ins>2</ins></p>`);
   cooked(`<abbr title="JavaScript">JS</abbr>`, `<p><abbr title="JavaScript">JS</abbr></p>`);
   cooked(`<dl><dt>Forum</dt><dd>Software</dd></dl>`, `<dl><dt>Forum</dt><dd>Software</dd></dl>`);
-  cooked(`<sup>high</sup> <sub>low</sub>`, `<p><sup>high</sup> <sub>low</sub></p>`);
+  cooked(`<sup>high</sup> <sub>low</sub> <big>HUGE</big>`, `<p><sup>high</sup> <sub>low</sub> <big>HUGE</big></p>`);
 });
 
 test("ids on headings", () => {