diff --git a/apps/dashboard/lib/Controller/DashboardApiController.php b/apps/dashboard/lib/Controller/DashboardApiController.php
index d31cede85b790..f920c384ba234 100644
--- a/apps/dashboard/lib/Controller/DashboardApiController.php
+++ b/apps/dashboard/lib/Controller/DashboardApiController.php
@@ -200,6 +200,7 @@ public function getLayout(): DataResponse {
 	#[NoAdminRequired]
 	#[ApiRoute(verb: 'POST', url: '/api/v3/layout')]
 	public function updateLayout(array $layout): DataResponse {
+		$layout = $this->service->sanitizeLayout($layout);
 		$this->config->setUserValue($this->userId, 'dashboard', 'layout', implode(',', $layout));
 		return new DataResponse(['layout' => $layout]);
 	}
diff --git a/apps/dashboard/lib/Service/DashboardService.php b/apps/dashboard/lib/Service/DashboardService.php
index bb5333c2cc77b..a0bbc475bc647 100644
--- a/apps/dashboard/lib/Service/DashboardService.php
+++ b/apps/dashboard/lib/Service/DashboardService.php
@@ -29,7 +29,28 @@ public function __construct(
 	 */
 	public function getLayout(): array {
 		$systemDefault = $this->config->getAppValue('dashboard', 'layout', 'recommendations,spreed,mail,calendar');
-		return array_values(array_filter(explode(',', $this->config->getUserValue($this->userId, 'dashboard', 'layout', $systemDefault)), fn (string $value) => $value !== ''));
+		return $this->sanitizeLayout(
+			explode(',', $this->config->getUserValue($this->userId, 'dashboard', 'layout', $systemDefault)),
+		);
+	}
+
+	/**
+	 * @param list<string> $layout
+	 * @return list<string>
+	 */
+	public function sanitizeLayout(array $layout): array {
+		$seen = [];
+		$result = [];
+		foreach ($layout as $value) {
+			if ($value === '' || isset($seen[$value])) {
+				continue;
+			}
+
+			$seen[$value] = true;
+			$result[] = $value;
+		}
+
+		return $result;
 	}
 
 	/**
diff --git a/apps/dashboard/tests/DashboardServiceTest.php b/apps/dashboard/tests/DashboardServiceTest.php
index ebcd06cdf033a..73a7906ec7fbd 100644
--- a/apps/dashboard/tests/DashboardServiceTest.php
+++ b/apps/dashboard/tests/DashboardServiceTest.php
@@ -40,6 +40,25 @@ protected function setUp(): void {
 		);
 	}
 
+	public function testGetLayoutRemovesEmptyAndDuplicateEntries(): void {
+		$this->appConfig->method('getAppValueString')
+			->with('layout', 'recommendations,spreed,mail,calendar')
+			->willReturn('recommendations,spreed,mail,calendar');
+		$this->userConfig->method('getValueString')
+			->with('alice', 'dashboard', 'layout', 'recommendations,spreed,mail,calendar')
+			->willReturn('spreed,,mail,mail,calendar,spreed');
+
+		$layout = $this->service->getLayout();
+
+		$this->assertSame(['spreed', 'mail', 'calendar'], $layout);
+	}
+
+	public function testSanitizeLayoutRemovesEmptyAndDuplicateEntries(): void {
+		$layout = $this->service->sanitizeLayout(['files', 'calendar', 'files', '', 'mail', 'calendar']);
+
+		$this->assertSame(['files', 'calendar', 'mail'], $layout);
+	}
+
 	public function testGetBirthdate(): void {
 		$user = $this->createMock(IUser::class);
 		$this->userManager->method('get')