diff --git a/app/assets/javascripts/pretty-text/pretty-text.js.es6 b/app/assets/javascripts/pretty-text/pretty-text.js.es6
index eb493b3640a..9c7a814940a 100644
--- a/app/assets/javascripts/pretty-text/pretty-text.js.es6
+++ b/app/assets/javascripts/pretty-text/pretty-text.js.es6
@@ -62,7 +62,7 @@ export function buildOptions(state) {
     lookupImageUrls,
     censoredWords,
     allowedHrefSchemes: siteSettings.allowed_href_schemes ? siteSettings.allowed_href_schemes.split('|') : null,
-    allowedIframes: (siteSettings.allowed_iframes || '').split('|'),
+    allowedIframes: siteSettings.allowed_iframes ? siteSettings.allowed_iframes.split('|') : [],
     markdownIt: true,
     previewing
   };
diff --git a/test/javascripts/lib/sanitizer-test.js.es6 b/test/javascripts/lib/sanitizer-test.js.es6
index cc5dcb205cb..8650bc90bae 100644
--- a/test/javascripts/lib/sanitizer-test.js.es6
+++ b/test/javascripts/lib/sanitizer-test.js.es6
@@ -4,7 +4,9 @@ import { hrefAllowed } from 'pretty-text/sanitizer';
 QUnit.module("lib:sanitizer");
 
 QUnit.test("sanitize", assert => {
-  const pt = new PrettyText(buildOptions({ siteSettings: {} }));
+  const pt = new PrettyText(buildOptions({ siteSettings: {
+    "allowed_iframes": 'https://www.google.com/maps/embed?|https://www.openstreetmap.org/export/embed.html?'
+  } }));
   const cooked = (input, expected, text) => assert.equal(pt.cook(input), expected.replace(/\/>/g, ">"), text);
 
   assert.equal(pt.sanitize("<i class=\"fa-bug fa-spin\">bug</i>"), "<i>bug</i>");
@@ -28,8 +30,8 @@ QUnit.test("sanitize", assert => {
          "<iframe src=\"https://www.google.com/maps/embed?pb=!1m10!1m8!1m3!1d2624.9983685732213!2d2.29432085!3d48.85824149999999!3m2!1i1024!2i768!4f13.1!5e0!3m2!1sen!2s!4v1385737436368\" width=\"100\" height=\"42\"></iframe>",
          "it allows iframe to google maps");
 
-  cooked("<iframe width=\"425\" height=\"350\" frameborder=\"0\" marginheight=\"0\" marginwidth=\"0\" src=\"http://www.openstreetmap.org/export/embed.html?bbox=22.49454975128174%2C51.220338322410775%2C22.523088455200195%2C51.23345342732931&amp;layer=mapnik\"></iframe>",
-         "<iframe width=\"425\" height=\"350\" frameborder=\"0\" marginheight=\"0\" marginwidth=\"0\" src=\"http://www.openstreetmap.org/export/embed.html?bbox=22.49454975128174%2C51.220338322410775%2C22.523088455200195%2C51.23345342732931&amp;layer=mapnik\"></iframe>",
+  cooked("<iframe width=\"425\" height=\"350\" frameborder=\"0\" marginheight=\"0\" marginwidth=\"0\" src=\"https://www.openstreetmap.org/export/embed.html?bbox=22.49454975128174%2C51.220338322410775%2C22.523088455200195%2C51.23345342732931&amp;layer=mapnik\"></iframe>",
+         "<iframe width=\"425\" height=\"350\" frameborder=\"0\" marginheight=\"0\" marginwidth=\"0\" src=\"https://www.openstreetmap.org/export/embed.html?bbox=22.49454975128174%2C51.220338322410775%2C22.523088455200195%2C51.23345342732931&amp;layer=mapnik\"></iframe>",
          "it allows iframe to OpenStreetMap");
 
   assert.equal(pt.sanitize("<textarea>hullo</textarea>"), "hullo");