diff --git a/app/assets/javascripts/vue_shared/components/markdown/header.vue b/app/assets/javascripts/vue_shared/components/markdown/header.vue
index 9efffb293ea5ad104a5d0c349d934e8ee61ee4a8..80bda07dc62cae30e37861e1bc676c8be3e55b0d 100644
--- a/app/assets/javascripts/vue_shared/components/markdown/header.vue
+++ b/app/assets/javascripts/vue_shared/components/markdown/header.vue
@@ -335,7 +335,7 @@ export default {
                 @replace="replaceTextarea"
               />
             </div>
-            <header-divider v-if="previewMarkdown || enablePreview" />
+            <header-divider v-if="enablePreview && !previewMarkdown" />
           </div>
           <toolbar-button
             v-show="!previewMarkdown"
diff --git a/spec/frontend/vue_shared/components/markdown/header_spec.js b/spec/frontend/vue_shared/components/markdown/header_spec.js
index 407a7476ab92be5935ccdf5f03afafacb005d70b..e7cf3ade3e277e7eacc67579dec88464457c6e4a 100644
--- a/spec/frontend/vue_shared/components/markdown/header_spec.js
+++ b/spec/frontend/vue_shared/components/markdown/header_spec.js
@@ -109,6 +109,12 @@ describe('Markdown field header component', () => {
     expect(findToolbar().findAllComponents(GlButton)).toHaveLength(1);
   });
 
+  it('hides divider in preview mode', () => {
+    createWrapper({ props: { previewMarkdown: true } });
+
+    expect(findDividers().length).toBe(0);
+  });
+
   it('emits toggle markdown event when clicking preview toggle', async () => {
     findPreviewToggle().vm.$emit('click', true);