diff --git a/content/docs/custom-widgets.md b/content/docs/custom-widgets.md
index 2874ed60..3ba6a956 100644
--- a/content/docs/custom-widgets.md
+++ b/content/docs/custom-widgets.md
@@ -145,7 +145,7 @@ CMS.registerEditorComponent({
   //
   // Additionally, it's recommended that you use non-greedy capturing groups (e.g.
   // `(.*?)` vs `(.*)`), especially if matching against newline characters.
-  pattern: /^<details>$\s*?<summary>(.*?)<\/summary>\n\n(.*?)\n^<\/details>$/ms,
+  pattern: /^<details><summary>(.*?)<\/summary>(.*?)<\/details>$/ms,
   // Given a RegExp Match object
   // (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/match#return_value),
   // return an object with one property for each field defined in `fields`.
@@ -163,14 +163,7 @@ CMS.registerEditorComponent({
   // This is used to serialize the data from the custom widget to the
   // markdown document
   toBlock: function(data) {
-    return `
-<details>
-  <summary>${data.summary}</summary>
-
-  ${data.contents}
-
-</details>
-`;
+    return `<details><summary>${data.summary}</summary>${data.contents}</details>`;
   },
   // Preview output for this component. Can either be a string or a React component
   // (component gives better render performance)