diff --git a/packages/components/src/panel/body.js b/packages/components/src/panel/body.js
index dbfd895dc8a61..2c297223a604a 100644
--- a/packages/components/src/panel/body.js
+++ b/packages/components/src/panel/body.js
@@ -82,6 +82,7 @@ const PanelBodyTitle = forwardRef(
 			<h2 className="components-panel__body-title">
 				<Button
 					className="components-panel__body-toggle"
+					aria-expanded={ isOpened }
 					ref={ ref }
 					{ ...props }
 				>
diff --git a/packages/edit-post/src/components/sidebar/plugin-post-publish-panel/test/__snapshots__/index.js.snap b/packages/edit-post/src/components/sidebar/plugin-post-publish-panel/test/__snapshots__/index.js.snap
index a7eb099d379a5..aafa7c918f179 100644
--- a/packages/edit-post/src/components/sidebar/plugin-post-publish-panel/test/__snapshots__/index.js.snap
+++ b/packages/edit-post/src/components/sidebar/plugin-post-publish-panel/test/__snapshots__/index.js.snap
@@ -1,3 +1,3 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`PluginPostPublishPanel renders fill properly 1`] = `"<div class=\\"components-panel__body my-plugin-post-publish-panel is-opened\\"><h2 class=\\"components-panel__body-title\\"><button type=\\"button\\" class=\\"components-button components-panel__body-toggle\\"><span aria-hidden=\\"true\\"><svg width=\\"24\\" height=\\"24\\" viewBox=\\"0 0 24 24\\" xmlns=\\"http://www.w3.org/2000/svg\\" class=\\"components-panel__arrow\\" role=\\"img\\" aria-hidden=\\"true\\" focusable=\\"false\\"><path d=\\"M12 8l-6 5.4 1 1.2 5-4.6 5 4.6 1-1.2z\\"></path></svg></span>My panel title</button></h2>My panel content</div>"`;
+exports[`PluginPostPublishPanel renders fill properly 1`] = `"<div class=\\"components-panel__body my-plugin-post-publish-panel is-opened\\"><h2 class=\\"components-panel__body-title\\"><button type=\\"button\\" aria-expanded=\\"true\\" class=\\"components-button components-panel__body-toggle\\"><span aria-hidden=\\"true\\"><svg width=\\"24\\" height=\\"24\\" viewBox=\\"0 0 24 24\\" xmlns=\\"http://www.w3.org/2000/svg\\" class=\\"components-panel__arrow\\" role=\\"img\\" aria-hidden=\\"true\\" focusable=\\"false\\"><path d=\\"M12 8l-6 5.4 1 1.2 5-4.6 5 4.6 1-1.2z\\"></path></svg></span>My panel title</button></h2>My panel content</div>"`;
diff --git a/packages/edit-post/src/components/sidebar/plugin-pre-publish-panel/test/__snapshots__/index.js.snap b/packages/edit-post/src/components/sidebar/plugin-pre-publish-panel/test/__snapshots__/index.js.snap
index f065917b0ee8a..6087ec62497e5 100644
--- a/packages/edit-post/src/components/sidebar/plugin-pre-publish-panel/test/__snapshots__/index.js.snap
+++ b/packages/edit-post/src/components/sidebar/plugin-pre-publish-panel/test/__snapshots__/index.js.snap
@@ -1,3 +1,3 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`PluginPrePublishPanel renders fill properly 1`] = `"<div class=\\"components-panel__body my-plugin-pre-publish-panel is-opened\\"><h2 class=\\"components-panel__body-title\\"><button type=\\"button\\" class=\\"components-button components-panel__body-toggle\\"><span aria-hidden=\\"true\\"><svg width=\\"24\\" height=\\"24\\" viewBox=\\"0 0 24 24\\" xmlns=\\"http://www.w3.org/2000/svg\\" class=\\"components-panel__arrow\\" role=\\"img\\" aria-hidden=\\"true\\" focusable=\\"false\\"><path d=\\"M12 8l-6 5.4 1 1.2 5-4.6 5 4.6 1-1.2z\\"></path></svg></span>My panel title</button></h2>My panel content</div>"`;
+exports[`PluginPrePublishPanel renders fill properly 1`] = `"<div class=\\"components-panel__body my-plugin-pre-publish-panel is-opened\\"><h2 class=\\"components-panel__body-title\\"><button type=\\"button\\" aria-expanded=\\"true\\" class=\\"components-button components-panel__body-toggle\\"><span aria-hidden=\\"true\\"><svg width=\\"24\\" height=\\"24\\" viewBox=\\"0 0 24 24\\" xmlns=\\"http://www.w3.org/2000/svg\\" class=\\"components-panel__arrow\\" role=\\"img\\" aria-hidden=\\"true\\" focusable=\\"false\\"><path d=\\"M12 8l-6 5.4 1 1.2 5-4.6 5 4.6 1-1.2z\\"></path></svg></span>My panel title</button></h2>My panel content</div>"`;