diff --git a/lib/private/Files/Storage/Local.php b/lib/private/Files/Storage/Local.php
index 005b5f9ab91f..317f25eddcf2 100644
--- a/lib/private/Files/Storage/Local.php
+++ b/lib/private/Files/Storage/Local.php
@@ -53,7 +53,12 @@ public function __construct($arguments) {
 			throw new \InvalidArgumentException('No data directory set for local storage');
 		}
 		$this->datadir = $arguments['datadir'];
-		$this->realDataDir = rtrim(realpath($this->datadir), '/') . '/';
+		// some crazy code uses a local storage on root...
+		if ($this->datadir === '/') {
+			$this->realDataDir = $this->datadir;
+		} else {
+			$this->realDataDir = rtrim(realpath($this->datadir), '/') . '/';
+		}
 		if (substr($this->datadir, -1) !== '/') {
 			$this->datadir .= '/';
 		}