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 1b529e6fb..2ff739cb4 100644
--- a/src/main/scala/li/cil/oc/server/component/FileSystem.scala
+++ b/src/main/scala/li/cil/oc/server/component/FileSystem.scala
@@ -245,7 +245,7 @@ class FileSystem(val fileSystem: IFileSystem, var label: Label, val host: Option
   def checkHandle(args: Arguments, index: Int) = {
     if (args.isInteger(index)) {
       args.checkInteger(index)
-    } else args.checkAny(0) match {
+    } else args.checkAny(index) match {
       case handle: HandleValue => handle.handle
       case _ => throw new IOException("bad file descriptor")
     }