diff --git a/common/content/editor.js b/common/content/editor.js
index 25dff89b..01a25ebd 100644
--- a/common/content/editor.js
+++ b/common/content/editor.js
@@ -470,7 +470,7 @@ var Editor = Module("editor", XPCOM(Ci.nsIEditActionListener, ModuleBase), {
         }
 
         try {
-            var tmpfile = io.createTempFile();
+            var tmpfile = io.createTempFile("txt", "." + buffer.uri.host);
             if (!tmpfile)
                 throw Error(_("io.cantCreateTempFile"));
 
diff --git a/common/modules/config.jsm b/common/modules/config.jsm
index 574f788f..9e5b7c0c 100644
--- a/common/modules/config.jsm
+++ b/common/modules/config.jsm
@@ -568,12 +568,6 @@ var ConfigBase = Class("ConfigBase", {
 
     sidebars: {},
 
-    /**
-     * @property {string} The leaf name of any temp files created by
-     *     {@link io.createTempFile}.
-     */
-    get tempFile() this.name + ".txt",
-
     /**
      * @constant
      * @property {string} The default highlighting rules.
diff --git a/common/modules/io.jsm b/common/modules/io.jsm
index f09a4d96..8a3a06b2 100644
--- a/common/modules/io.jsm
+++ b/common/modules/io.jsm
@@ -307,23 +307,20 @@ var IO = Module("io", {
     },
 
     /**
-     * Creates a temporary file.
+     * Returns a temporary file.
      *
+     * @param {string} ext The filename extension.
+     *     @default "txt"
+     * @param {string} label A metadata string appended to the filename. Useful
+     *     for identifying the file, beyond its extension, to external
+     *     applications.
+     *     @default ""
      * @returns {File}
      */
-    createTempFile: function createTempFile(name, type) {
-        if (name instanceof Ci.nsIFile) {
-            var file = name.clone();
-            if (!type || type == "file")
-                file.createUnique(Ci.nsIFile.NORMAL_FILE_TYPE, octal(666));
-            else
-                file.createUnique(Ci.nsIFile.DIRECTORY_TYPE, octal(777));
-        }
-        else {
-            file = services.directory.get("TmpD", Ci.nsIFile);
-            file.append(this.config.tempFile + (name ? "." + name : ""));
-            file.createUnique(Ci.nsIFile.NORMAL_FILE_TYPE, octal(666));
-        }
+    createTempFile: function createTempFile(ext = "txt", label = "") {
+        let file = services.directory.get("TmpD", Ci.nsIFile);
+        file.append(config.name + label + "." + ext);
+        file.createUnique(Ci.nsIFile.NORMAL_FILE_TYPE, octal(666));
 
         services.externalApp.deleteTemporaryFileOnExit(file);
 
@@ -543,9 +540,9 @@ var IO = Module("io", {
      * @returns {boolean} false if temp files couldn't be created,
      *     otherwise, the return value of *func*.
      */
-    withTempFiles: function withTempFiles(func, self, checked, ext) {
+    withTempFiles: function withTempFiles(func, self, checked, ext, label) {
         let args = array(util.range(0, func.length))
-                    .map(bind("createTempFile", this, ext)).array;
+                    .map(bind("createTempFile", this, ext, label)).array;
         try {
             if (!args.every(util.identity))
                 return false;
diff --git a/pentadactyl/content/config.js b/pentadactyl/content/config.js
index 2dde4bc1..183f6d10 100644
--- a/pentadactyl/content/config.js
+++ b/pentadactyl/content/config.js
@@ -79,16 +79,6 @@ var Config = Module("config", ConfigBase, {
                 else
                     dactyl.beep();
             }
-        },
-
-        get tempFile() {
-            let prefix = this.name;
-            try {
-                prefix += "-" + window.content.document.location.hostname;
-            }
-            catch (e) {}
-
-            return prefix + ".txt";
         }
     })
 
diff --git a/teledactyl/content/config.js b/teledactyl/content/config.js
index 6c85f30d..72215c86 100644
--- a/teledactyl/content/config.js
+++ b/teledactyl/content/config.js
@@ -116,10 +116,7 @@ var Config = Module("config", ConfigBase, {
                     modes.main = modes.MESSAGE;
             }
         }
-    },
-
-    // to allow Vim to :set ft=mail automatically
-    tempFile: "teledactyl.eml"
+    }
 }, {
 }, {
     commands: function initCommands(dactyl, modules, window) {