diff --git a/app/assets/javascripts/pretty-text/engines/discourse-markdown/html.js.es6 b/app/assets/javascripts/pretty-text/engines/discourse-markdown/html.js.es6
index 64a237ca464..0e5c5e4a18c 100644
--- a/app/assets/javascripts/pretty-text/engines/discourse-markdown/html.js.es6
+++ b/app/assets/javascripts/pretty-text/engines/discourse-markdown/html.js.es6
@@ -1,7 +1,7 @@
 const BLOCK_TAGS = ['address', 'article', 'aside', 'audio', 'blockquote', 'canvas', 'dd', 'details',
                     'div', 'dl', 'fieldset', 'figcaption', 'figure', 'footer', 'form', 'h1', 'h2', 'h3',
                     'h4', 'h5', 'h6', 'header', 'hgroup', 'hr', 'iframe', 'noscript', 'ol', 'output',
-                    'p', 'pre', 'section', 'table', 'tfoot', 'ul', 'video'];
+                    'p', 'pre', 'section', 'table', 'tfoot', 'ul', 'video', 'summary'];
 
 function splitAtLast(tag, block, next, first) {
   const endTag = `</${tag}>`;
@@ -34,7 +34,7 @@ export function setup(helper) {
       }
     }
 
-    const m = /^<([^>]+)\>/.exec(block);
+    const m = /^\s*<\/?([^>]+)\>/.exec(block);
     if (m && m[1]) {
       const tag = m[1].split(/\s/);
       if (tag && tag[0] && BLOCK_TAGS.indexOf(tag[0]) !== -1) {
diff --git a/plugins/poll/test/javascripts/controllers/poll-ui-builder-test.js.es6 b/plugins/poll/test/javascripts/controllers/poll-ui-builder-test.js.es6
index fe263538c53..59e8d9266d4 100644
--- a/plugins/poll/test/javascripts/controllers/poll-ui-builder-test.js.es6
+++ b/plugins/poll/test/javascripts/controllers/poll-ui-builder-test.js.es6
@@ -57,11 +57,11 @@ test("pollOptionsCount", function() {
   const controller = this.subject();
   controller.siteSettings = Discourse.SiteSettings;
 
-  controller.set("pollOptions", "1\n2\n")
+  controller.set("pollOptions", "1\n2\n");
 
   equal(controller.get("pollOptionsCount"), 2, "it should equal 2");
 
-  controller.set("pollOptions", "")
+  controller.set("pollOptions", "");
 
   equal(controller.get("pollOptionsCount"), 0, "it should equal 0");
 });
diff --git a/test/javascripts/lib/pretty-text-test.js.es6 b/test/javascripts/lib/pretty-text-test.js.es6
index e4ef370a01e..9549d06566b 100644
--- a/test/javascripts/lib/pretty-text-test.js.es6
+++ b/test/javascripts/lib/pretty-text-test.js.es6
@@ -696,3 +696,13 @@ test("emoji - emojiSet", () => {
                 { emojiSet: 'twitter' },
                 `<p><img src="/images/emoji/twitter/smile.png?v=${v}" title=":smile:" class="emoji" alt=":smile:"></p>`);
 });
+
+test("details", () => {
+  cooked(`<details><summary>Info</summary>coucou</details>`,
+         `<details><summary>Info</summary>\n\n<p>coucou</p>\n\n</details>`,
+         "manual HTML for details");
+  cooked(` <details><summary>Info</summary>coucou</details>`,
+         `<details><summary>Info</summary>\n\n<p>coucou</p>\n\n</details>`,
+         "manual HTML for details with a space");
+});
+