diff --git a/x-pack/plugins/security_solution/public/detections/components/rules/step_about_rule_details/index.test.tsx b/x-pack/plugins/security_solution/public/detections/components/rules/step_about_rule_details/index.test.tsx
index 8e398e6236510a6..757319e7aa1ae91 100644
--- a/x-pack/plugins/security_solution/public/detections/components/rules/step_about_rule_details/index.test.tsx
+++ b/x-pack/plugins/security_solution/public/detections/components/rules/step_about_rule_details/index.test.tsx
@@ -154,7 +154,9 @@ describe('StepAboutRuleToggleDetails', () => {
         .simulate('change', { target: { value: 'notes' } });
 
       expect(wrapper.find('EuiButtonGroup[idSelected="notes"]').exists()).toBeTruthy();
-      expect(wrapper.find('Markdown h1').text()).toEqual('this is some markdown documentation');
+      expect(wrapper.find('.euiMarkdownFormat').text()).toEqual(
+        'this is some markdown documentation'
+      );
     });
   });
 });
diff --git a/x-pack/plugins/security_solution/public/timelines/components/notes/add_note/__snapshots__/index.test.tsx.snap b/x-pack/plugins/security_solution/public/timelines/components/notes/add_note/__snapshots__/index.test.tsx.snap
index 718e7ce1d27a5a3..53bc76bfeb8e862 100644
--- a/x-pack/plugins/security_solution/public/timelines/components/notes/add_note/__snapshots__/index.test.tsx.snap
+++ b/x-pack/plugins/security_solution/public/timelines/components/notes/add_note/__snapshots__/index.test.tsx.snap
@@ -11,13 +11,6 @@ exports[`AddNote renders correctly 1`] = `
     noteInputHeight={200}
     updateNewNote={[MockFunction]}
   />
-  <EuiFlexItem
-    grow={true}
-  >
-    <MarkdownHint
-      show={true}
-    />
-  </EuiFlexItem>
   <ButtonsContainer
     gutterSize="none"
   >
diff --git a/x-pack/plugins/security_solution/public/timelines/components/notes/add_note/__snapshots__/new_note.test.tsx.snap b/x-pack/plugins/security_solution/public/timelines/components/notes/add_note/__snapshots__/new_note.test.tsx.snap
index 9bf2b5c65e82944..69e06bc7e0d1bce 100644
--- a/x-pack/plugins/security_solution/public/timelines/components/notes/add_note/__snapshots__/new_note.test.tsx.snap
+++ b/x-pack/plugins/security_solution/public/timelines/components/notes/add_note/__snapshots__/new_note.test.tsx.snap
@@ -3,54 +3,13 @@
 exports[`NewNote renders correctly 1`] = `
 <NewNoteTabs
   data-test-subj="new-note-tabs"
-  initialSelectedTab={
-    Object {
-      "content": <TextArea
-        aria-label="Note"
-        autoFocus={true}
-        data-test-subj="add-a-note"
-        fullWidth={true}
-        height={200}
-        onChange={[Function]}
-        placeholder="Add a Note"
-        spellCheck={true}
-        value="The contents of a new note"
-      />,
-      "id": "note",
-      "name": "Note",
-    }
-  }
-  tabs={
-    Array [
-      Object {
-        "content": <TextArea
-          aria-label="Note"
-          autoFocus={true}
-          data-test-subj="add-a-note"
-          fullWidth={true}
-          height={200}
-          onChange={[Function]}
-          placeholder="Add a Note"
-          spellCheck={true}
-          value="The contents of a new note"
-        />,
-        "id": "note",
-        "name": "Note",
-      },
-      Object {
-        "content": <MarkdownContainer
-          data-test-subj="markdown-container"
-          height={200}
-          paddingSize="s"
-        >
-          <Memo(Markdown)
-            raw="The contents of a new note"
-          />
-        </MarkdownContainer>,
-        "id": "preview",
-        "name": "Preview (Markdown)",
-      },
-    ]
-  }
-/>
+>
+  <Memo(MarkdownEditorComponent)
+    ariaLabel="Note"
+    dataTestSubj="add-a-note"
+    height={200}
+    onChange={[MockFunction]}
+    value="The contents of a new note"
+  />
+</NewNoteTabs>
 `;
diff --git a/x-pack/plugins/security_solution/public/timelines/components/notes/add_note/index.test.tsx b/x-pack/plugins/security_solution/public/timelines/components/notes/add_note/index.test.tsx
index 570c0028e0f5161..01dfd72a22db1b8 100644
--- a/x-pack/plugins/security_solution/public/timelines/components/notes/add_note/index.test.tsx
+++ b/x-pack/plugins/security_solution/public/timelines/components/notes/add_note/index.test.tsx
@@ -74,7 +74,9 @@ describe('AddNote', () => {
   test('it renders the contents of the note', () => {
     const wrapper = mount(<AddNote {...props} />);
 
-    expect(wrapper.find('[data-test-subj="add-a-note"]').first().text()).toEqual(note);
+    expect(
+      wrapper.find('[data-test-subj="add-a-note"] .euiMarkdownEditorDropZone').first().text()
+    ).toEqual(note);
   });
 
   test('it invokes associateNote when the Add Note button is clicked', () => {
@@ -131,30 +133,4 @@ describe('AddNote', () => {
 
     expect(updateNote).toBeCalled();
   });
-
-  test('it does NOT display the markdown formatting hint when a note has NOT been entered', () => {
-    const testProps = {
-      ...props,
-      newNote: '',
-    };
-    const wrapper = mount(<AddNote {...testProps} />);
-
-    expect(wrapper.find('[data-test-subj="markdown-hint"]').first()).toHaveStyleRule(
-      'visibility',
-      'hidden'
-    );
-  });
-
-  test('it displays the markdown formatting hint when a note has been entered', () => {
-    const testProps = {
-      ...props,
-      newNote: 'We should see a formatting hint now',
-    };
-    const wrapper = mount(<AddNote {...testProps} />);
-
-    expect(wrapper.find('[data-test-subj="markdown-hint"]').first()).toHaveStyleRule(
-      'visibility',
-      'inline'
-    );
-  });
 });
diff --git a/x-pack/plugins/security_solution/public/timelines/components/notes/add_note/new_note.test.tsx b/x-pack/plugins/security_solution/public/timelines/components/notes/add_note/new_note.test.tsx
index c85d9b7dca75caa..0377653ae3b646e 100644
--- a/x-pack/plugins/security_solution/public/timelines/components/notes/add_note/new_note.test.tsx
+++ b/x-pack/plugins/security_solution/public/timelines/components/notes/add_note/new_note.test.tsx
@@ -7,8 +7,6 @@
 import { mount, shallow } from 'enzyme';
 import React from 'react';
 
-import * as i18n from '../translations';
-
 import { NewNote } from './new_note';
 
 describe('NewNote', () => {
@@ -21,36 +19,11 @@ describe('NewNote', () => {
     expect(wrapper).toMatchSnapshot();
   });
 
-  test('it renders a tab labeled "Note"', () => {
-    const wrapper = mount(<NewNote noteInputHeight={200} note={note} updateNewNote={jest.fn()} />);
-
-    expect(wrapper.find('button[role="tab"]').first().text()).toEqual(i18n.NOTE);
-  });
-
-  test('it renders a tab labeled "Preview (Markdown)"', () => {
-    const wrapper = mount(<NewNote noteInputHeight={200} note={note} updateNewNote={jest.fn()} />);
-
-    expect(wrapper.find('button[role="tab"]').at(1).text()).toEqual(i18n.PREVIEW_MARKDOWN);
-  });
-
-  test('it renders the expected placeholder when a note is NOT provided', () => {
-    const wrapper = mount(<NewNote noteInputHeight={200} note={''} updateNewNote={jest.fn()} />);
-
-    expect(wrapper.find(`textarea[placeholder="${i18n.ADD_A_NOTE}"]`).exists()).toEqual(true);
-  });
-
   test('it renders a text area containing the contents of a new (raw) note', () => {
     const wrapper = mount(<NewNote noteInputHeight={200} note={note} updateNewNote={jest.fn()} />);
 
-    expect(wrapper.find('[data-test-subj="add-a-note"]').first().text()).toEqual(note);
-  });
-
-  test('it renders a markdown preview when the user clicks Preview (Markdown)', () => {
-    const wrapper = mount(<NewNote noteInputHeight={200} note={note} updateNewNote={jest.fn()} />);
-
-    // click the preview tab:
-    wrapper.find('button[role="tab"]').at(1).simulate('click');
-
-    expect(wrapper.find('[data-test-subj="markdown-root"]').first().text()).toEqual(note);
+    expect(
+      wrapper.find('[data-test-subj="add-a-note"] .euiMarkdownEditorDropZone').first().text()
+    ).toEqual(note);
   });
 });
diff --git a/x-pack/plugins/security_solution/public/timelines/components/notes/note_cards/index.test.tsx b/x-pack/plugins/security_solution/public/timelines/components/notes/note_cards/index.test.tsx
index 5506514999f35f8..54a074bb2adb7ae 100644
--- a/x-pack/plugins/security_solution/public/timelines/components/notes/note_cards/index.test.tsx
+++ b/x-pack/plugins/security_solution/public/timelines/components/notes/note_cards/index.test.tsx
@@ -83,7 +83,7 @@ describe('NoteCards', () => {
       wrapper
         .find('[data-test-subj="note-card"]')
         .find('[data-test-subj="note-card-body"]')
-        .find('[data-test-subj="markdown-root"]')
+        .find('.euiMarkdownFormat')
         .first()
         .text()
     ).toEqual(getNotesByIds(noteIds)[0].note);