diff --git a/src/main/scala/li/cil/oc/server/component/FileSystem.scala b/src/main/scala/li/cil/oc/server/component/FileSystem.scala
index 4c9f87fe4..ec43a01c1 100644
--- a/src/main/scala/li/cil/oc/server/component/FileSystem.scala
+++ b/src/main/scala/li/cil/oc/server/component/FileSystem.scala
@@ -320,7 +320,7 @@ class FileSystem(val fileSystem: IFileSystem, var label: Label, val host: Option
 
   private def clean(path: String) = {
     val result = com.google.common.io.Files.simplifyPath(path)
-    if (result.startsWith("../")) throw new FileNotFoundException(path)
+    if (result.startsWith("../") || result == "..") throw new FileNotFoundException(path)
     if (result == "/" || result == ".") ""
     else result
   }