diff --git a/tests/unit/Service/ApiServiceTest.php b/tests/unit/Service/ApiServiceTest.php
index 83a4b848c84..df3ae4e63be 100644
--- a/tests/unit/Service/ApiServiceTest.php
+++ b/tests/unit/Service/ApiServiceTest.php
@@ -3,6 +3,7 @@
 namespace OCA\Text\Tests;
 
 use OCA\Text\Db\Document;
+use OCA\Text\Db\Session;
 use OCA\Text\Service\ApiService;
 use OCA\Text\Service\ConfigService;
 use OCA\Text\Service\DocumentService;
@@ -66,6 +67,29 @@ public function testCreateNewSessionWithoutOwner() {
 		self::assertFalse($actual->getData()['hasOwner']);
 	}
 
+	public function testSaveWithNotPermittedException() {
+		$session = new Session();
+		$session->setDocumentId(123);
+
+		$document = new Document();
+
+		$file = $this->mockFile(123, 'admin');
+
+		$this->documentService->method('getFileForSession')->willReturn($file);
+		$this->documentService->method('autosave')->willThrowException(new  \OCP\Files\NotPermittedException());
+
+		$this->l10n->method('t')
+			->with('Read-only permission cannot save document changes. Please reload the page.')
+			->willReturn('Read-only permission cannot save document changes. Please reload the page.');
+
+		$response = $this->apiService->save($session, $document, 1, 'content', 'state');
+
+		self::assertEquals(\OCP\AppFramework\Http::STATUS_FORBIDDEN, $response->getStatus());
+		self::assertEquals('Read-only permission cannot save document changes. Please reload the page.',
+			$response->getData()['error']
+		);
+	}
+
 	private function mockFile(int $id, ?string $owner) {
 		$file = $this->createMock(\OCP\Files\File::class);
 		$storage = $this->createMock(\OCP\Files\Storage\IStorage::class);