diff --git a/common/bootstrap.js b/common/bootstrap.js
index 813440ac..34fb8802 100755
--- a/common/bootstrap.js
+++ b/common/bootstrap.js
@@ -45,6 +45,7 @@ let initialized = false;
 let addon = null;
 let basePath = null;
 let components = {};
+let resources = [];
 let getURI = null;
 storage.set("dactyl.bootstrap", this);
 
@@ -139,6 +140,7 @@ function init() {
             break;
 
         case "resource":
+            resources.push(fields[1]);
             resourceProto.setSubstitution(fields[1], getURI(fields[2]));
         }
     }
@@ -174,6 +176,10 @@ function shutdown(data, reason) {
 
         services.observer.notifyObservers(null, "dactyl-cleanup", null);
         services.observer.notifyObservers(null, "dactyl-cleanup-modules", null);
+
+        JSMLoader.purge();
+        for each (let resource in resources)
+            resourceProto.setSubstitution(resource, null);
     }
 }
 
diff --git a/common/modules/bootstrap.jsm b/common/modules/bootstrap.jsm
index dac2201f..5609bf68 100644
--- a/common/modules/bootstrap.jsm
+++ b/common/modules/bootstrap.jsm
@@ -36,22 +36,12 @@ if (!JSMLoader || JSMLoader.bump != 1)
                 delete this.stale[url];
 
                 let global = this.globals[url];
-                for each (let prop in Object.getOwnPropertyNames(global))
-                    try {
-                        if (!(prop in this.builtin) && ["JSMLoader", "set"].indexOf(prop) < 0 &&
-                            !global.__lookupGetter__(prop))
-                            global[prop] = undefined;
-                    }
-                    catch (e) {
-                        dump("Deleting property " + prop + " on " + url + ":\n    " + e + "\n");
-                        Components.utils.reportError(e);
-                    }
-
                 if (stale === this.getTarget(url))
                     Components.classes["@mozilla.org/moz/jssubscript-loader;1"]
                               .getService(Components.interfaces.mozIJSSubScriptLoader)
                               .loadSubScript(url, global.global || global);
             }
+
             try {
                 let global = Components.utils.import(url, target);
 
@@ -73,9 +63,23 @@ if (!JSMLoader || JSMLoader.bump != 1)
                 this.manager.unregisterFactory(factory.classID, factory);
         },
         purge: function purge() {
-            for (let [url, global] in Iterator(this.globals))
+            for (let [url, global] in Iterator(this.globals)) {
                 this.stale[url] = this.getTarget(url);
+
+                for each (let prop in Object.getOwnPropertyNames(global))
+                    try {
+                        if (!(prop in this.builtin) &&
+                            ["JSMLoader", "set", "EXPORTED_SYMBOLS"].indexOf(prop) < 0 &&
+                            !global.__lookupGetter__(prop))
+                            global[prop] = undefined;
+                    }
+                    catch (e) {
+                        dump("Deleting property " + prop + " on " + url + ":\n    " + e + "\n");
+                        Components.utils.reportError(e);
+                    }
+            }
         },
+
         registerFactory: function registerFactory(factory) {
             this.manager.registerFactory(factory.classID,
                                          String(factory.classID),
diff --git a/common/modules/util.jsm b/common/modules/util.jsm
index eb247eac..eaa817d5 100644
--- a/common/modules/util.jsm
+++ b/common/modules/util.jsm
@@ -965,9 +965,7 @@ var Util = Module("Util", XPCOM([Ci.nsIObserver, Ci.nsISupportsWeakReference]),
             services.observer.removeObserver(this, "dactyl-rehash");
 
             defineModule.loadLog.push("dactyl: util: observe: dactyl-rehash");
-            if (this.rehashing)
-                JSMLoader.purge();
-            else
+            if (!this.rehashing)
                 for (let module in values(defineModule.modules)) {
                     defineModule.loadLog.push("dactyl: util: init(" + module + ")");
                     if (module.reinit)
@@ -978,7 +976,6 @@ var Util = Module("Util", XPCOM([Ci.nsIObserver, Ci.nsISupportsWeakReference]),
         },
         "dactyl-purge": function () {
             this.rehashing = 1;
-            JSMLoader.purge();
         },
         "toplevel-window-ready": function (window, data) {
             window.addEventListener("DOMContentLoaded", wrapCallback(function listener(event) {