diff --git a/apps/files_sharing/lib_share.php b/apps/files_sharing/lib_share.php
index 494f48db41ac1a39b71a15baa95f99d3ecbc2ddb..804379f8305e04a3721302b96cc2d7f52ee37a1a 100644
--- a/apps/files_sharing/lib_share.php
+++ b/apps/files_sharing/lib_share.php
@@ -137,7 +137,11 @@ class OC_SHARE {
 			return $result[0]['source'];
 		} else {
 			$folders = OC_SHARE::getParentFolders($target, false);
-			return $folders['source'].substr($target, strlen($folders['target']));
+			if ($folders == false) {
+				return false;
+			} else {
+				return $folders['source'].substr($target, strlen($folders['target']));
+			}
 		}
 	}