diff --git a/tests/lib/Files/ViewTest.php b/tests/lib/Files/ViewTest.php
index a6a7722f363..7d8c9e24802 100644
--- a/tests/lib/Files/ViewTest.php
+++ b/tests/lib/Files/ViewTest.php
@@ -1185,6 +1185,9 @@ class ViewTest extends \Test\TestCase {
 		$storage2->method('writeStream')
 			->willThrowException(new GenericFileException('Failed to copy stream'));
 
+		$storage2->method('fopen')
+			->willReturn(false);
+
 		$storage1->mkdir('sub');
 		$storage1->file_put_contents('foo.txt', '0123456789ABCDEFGH');
 		$storage1->mkdir('dirtomove');