diff --git a/lib/private/largefilehelper.php b/lib/private/largefilehelper.php
index 293e09fe2c..2c35feefc8 100644
--- a/lib/private/largefilehelper.php
+++ b/lib/private/largefilehelper.php
@@ -147,7 +147,7 @@ class LargeFileHelper {
 		if (\OC_Helper::is_function_enabled('exec')) {
 			$os = strtolower(php_uname('s'));
 			$arg = escapeshellarg($filename);
-			$result = '';
+			$result = null;
 			if (strpos($os, 'linux') !== false) {
 				$result = $this->exec("stat -c %s $arg");
 			} else if (strpos($os, 'bsd') !== false) {