diff --git a/apps/server/src/collaboration/collaboration.util.spec.ts b/apps/server/src/collaboration/collaboration.util.spec.ts
deleted file mode 100644
index 7115e7c10..000000000
--- a/apps/server/src/collaboration/collaboration.util.spec.ts
+++ /dev/null
@@ -1,54 +0,0 @@
-import { jsonToMarkdown } from './collaboration.util';
-
-const cell = (type: 'tableHeader' | 'tableCell', text: string) => ({
-  type,
-  content: [
-    {
-      type: 'paragraph',
-      content: text ? [{ type: 'text', text }] : [],
-    },
-  ],
-});
-
-const row = (type: 'tableHeader' | 'tableCell', texts: string[]) => ({
-  type: 'tableRow',
-  content: texts.map((text) => cell(type, text)),
-});
-
-const tableDoc = (rows: ReturnType<typeof row>[]) => ({
-  type: 'doc',
-  content: [{ type: 'table', content: rows }],
-});
-
-describe('jsonToMarkdown', () => {
-  it('uses the table header row as the markdown header', () => {
-    const markdown = jsonToMarkdown(
-      tableDoc([
-        row('tableHeader', ['Name', 'Role']),
-        row('tableCell', ['Ada', 'Engineer']),
-      ]),
-    );
-
-    expect(markdown.trim().split('\n')).toEqual([
-      '| Name | Role |',
-      '| --- | --- |',
-      '| Ada | Engineer |',
-    ]);
-  });
-
-  it('adds an empty header when the table has no header row', () => {
-    const markdown = jsonToMarkdown(
-      tableDoc([
-        row('tableCell', ['Ada', 'Engineer']),
-        row('tableCell', ['Alan', 'Mathematician']),
-      ]),
-    );
-
-    expect(markdown.trim().split('\n')).toEqual([
-      '|     |     |',
-      '| --- | --- |',
-      '| Ada | Engineer |',
-      '| Alan | Mathematician |',
-    ]);
-  });
-});
diff --git a/apps/server/src/integrations/export/html-to-markdown.spec.ts b/apps/server/src/integrations/export/html-to-markdown.spec.ts
new file mode 100644
index 000000000..8e4e43d04
--- /dev/null
+++ b/apps/server/src/integrations/export/html-to-markdown.spec.ts
@@ -0,0 +1,54 @@
+import { htmlToMarkdown } from '@docmost/editor-ext';
+
+const colgroup =
+  '<colgroup><col style="min-width: 25px;" /><col style="min-width: 25px;" /></colgroup>';
+
+describe('htmlToMarkdown', () => {
+  it('uses the table header row as the markdown header', () => {
+    const markdown = htmlToMarkdown(
+      `<table>${colgroup}<tbody>` +
+        '<tr><th><p>Name</p></th><th><p>Role</p></th></tr>' +
+        '<tr><td><p>Ada</p></td><td><p>Engineer</p></td></tr>' +
+        '</tbody></table>',
+    );
+
+    expect(markdown.trim().split('\n')).toEqual([
+      '| Name | Role |',
+      '| --- | --- |',
+      '| Ada | Engineer |',
+    ]);
+  });
+
+  it('adds an empty header when the table has no header row', () => {
+    const markdown = htmlToMarkdown(
+      `<table>${colgroup}<tbody>` +
+        '<tr><td><p>Ada</p></td><td><p>Engineer</p></td></tr>' +
+        '<tr><td><p>Alan</p></td><td><p>Mathematician</p></td></tr>' +
+        '</tbody></table>',
+    );
+
+    expect(markdown.trim().split('\n')).toEqual([
+      '|     |     |',
+      '| --- | --- |',
+      '| Ada | Engineer |',
+      '| Alan | Mathematician |',
+    ]);
+  });
+
+  it('marks details blocks so their content is parsed as markdown', () => {
+    const markdown = htmlToMarkdown(
+      '<details><summary data-type="detailsSummary">Title</summary>' +
+        '<div data-type="detailsContent"><p>Some <strong>bold</strong></p></div>' +
+        '</details>',
+    );
+
+    expect(markdown.trim().split('\n')).toEqual([
+      '<details markdown="1">',
+      '<summary>Title</summary>',
+      '',
+      'Some **bold**',
+      '',
+      '</details>',
+    ]);
+  });
+});
diff --git a/packages/editor-ext/src/lib/markdown/utils/turndown.utils.ts b/packages/editor-ext/src/lib/markdown/utils/turndown.utils.ts
index 8316c1bf3..3914d792b 100644
--- a/packages/editor-ext/src/lib/markdown/utils/turndown.utils.ts
+++ b/packages/editor-ext/src/lib/markdown/utils/turndown.utils.ts
@@ -150,7 +150,7 @@ function preserveDetail(turndownService: _TurndownService) {
         )
         .join('');
 
-      return `\n<details>\n${detailSummary}\n\n${detailsContent}\n\n</details>\n`;
+      return `\n<details markdown="1">\n${detailSummary}\n\n${detailsContent}\n\n</details>\n`;
     },
   });
 }