diff --git a/common/modules/base.jsm b/common/modules/base.jsm
index 13296528..e368811c 100644
--- a/common/modules/base.jsm
+++ b/common/modules/base.jsm
@@ -19,7 +19,7 @@ function module(url) {
 var { XPCOMUtils } = module("resource://gre/modules/XPCOMUtils.jsm");
 var { OS, TextDecoder, TextEncoder } = module("resource://gre/modules/osfile.jsm");
 try {
-    var ctypes = module("resource://gre/modules/ctypes.jsm");
+    var { ctypes } = module("resource://gre/modules/ctypes.jsm");
 }
 catch (e) {}
 
@@ -310,6 +310,7 @@ function properties(obj, prototypes) {
             else if (!e.stack) {
                 throw Error(e);
             }
+            throw e;
         }
     }
 
diff --git a/common/modules/storage.jsm b/common/modules/storage.jsm
index 5420564d..f1d1a30f 100644
--- a/common/modules/storage.jsm
+++ b/common/modules/storage.jsm
@@ -451,9 +451,9 @@ var File = Class("File", {
     /**
      * Returns a new file for the given child of this directory entry.
      */
-    child: function child() {
+    child: function child(...args) {
         let f = this.constructor(this);
-        for (let [, name] in Iterator(arguments))
+        for (let name of args)
             for (let elem of name.split(File.pathSplit))
                 f.append(elem);
         return f;