diff --git a/packages/frontend/src/boot/common.ts b/packages/frontend/src/boot/common.ts
index 4becf32ab5..b5e6aebdc2 100644
--- a/packages/frontend/src/boot/common.ts
+++ b/packages/frontend/src/boot/common.ts
@@ -106,6 +106,11 @@ export async function common(createVue: () => Promise<App<Element>>) {
 		window.history.replaceState(null, '', window.location.href.replace('#pswp', ''));
 	}
 
+	// URLに#folder-を含む場合は取り除く（FolderPageView用）
+	if (window.location.hash.startsWith('#folder-')) {
+		window.history.replaceState(null, '', window.location.href.replace(window.location.hash, ''));
+	}
+
 	// 一斉リロード
 	reloadChannel.addEventListener('message', path => {
 		if (path !== null) window.location.href = path;
diff --git a/packages/frontend/src/components/MkFolderPage.vue b/packages/frontend/src/components/MkFolderPage.vue
index 21700c9dd8..33816ba8c1 100644
--- a/packages/frontend/src/components/MkFolderPage.vue
+++ b/packages/frontend/src/components/MkFolderPage.vue
@@ -27,7 +27,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 </template>
 
 <script lang="ts" setup>
-import { onMounted, ref } from 'vue';
+import { onMounted, onUnmounted, ref } from 'vue';
 import { claimZIndex } from '@/os.js';
 import { prefer } from '@/preferences.js';
 
@@ -49,9 +49,34 @@ function closePage() {
 }
 
 function onClosed() {
+	// When closing, remove our history entry if we're still on our hash
+	if (window.location.hash === `#folder-${props.pageId}`) {
+		window.history.back();
+	}
 	emit('closed');
 }
 
+function popstateHandler(): void {
+	// If the hash is no longer our folder hash, close the page
+	if (window.location.hash !== `#folder-${props.pageId}`) {
+		closePage();
+	}
+}
+
+onMounted(() => {
+	// Push a new history state with a unique hash when the folder page opens
+	const folderHash = `#folder-${props.pageId}`;
+	window.history.pushState(null, '', folderHash);
+	
+	// Listen for popstate events (browser back button)
+	window.addEventListener('popstate', popstateHandler);
+});
+
+onUnmounted(() => {
+	// Clean up the event listener
+	window.removeEventListener('popstate', popstateHandler);
+});
+
 </script>
 
 <style lang="scss" module>