diff --git a/common/content/buffer.js b/common/content/buffer.js
index 5a902d79..999e1710 100644
--- a/common/content/buffer.js
+++ b/common/content/buffer.js
@@ -425,7 +425,7 @@ var Buffer = Module("buffer", {
     /**
      * @property {string} The current top-level document's URL.
      */
-    get URL() update(content.location.href, util.newURI(content.location.href)),
+    get URL() update(new String(content.location.href), util.newURI(content.location.href)),
 
     /**
      * @property {number} The buffer's height in pixels.
diff --git a/common/modules/io.jsm b/common/modules/io.jsm
index a60c4ea5..f98c363f 100644
--- a/common/modules/io.jsm
+++ b/common/modules/io.jsm
@@ -921,7 +921,7 @@ unlet s:cpo_save
                               isDirectory: function () s.substr(-1) == "/",
                               leafName: /([^\/]*)\/?$/.exec(s)[1]
                         }
-                        for (s in io.listJar(getDir(uri.JARFile, uri.JAREntry)))]
+                        for (s in io.listJar(uri.JARFile, getDir(uri.JAREntry)))]
                 };
             else
                 context.generate = function generate_file() {