diff --git a/common/content/dactyl.js b/common/content/dactyl.js
index a54b577b..9cc5fcea 100644
--- a/common/content/dactyl.js
+++ b/common/content/dactyl.js
@@ -1877,6 +1877,27 @@ var Dactyl = Module("dactyl", XPCOM(Ci.nsISupportsWeakReference, ModuleBase), {
         userContext.DOM = Class("DOM", DOM, { init: function DOM_(sel, ctxt) DOM(sel, ctxt || buffer.focusedFrame.document) });
         userContext.$ = modules.userContext.DOM;
 
+        // Hack: disable disabling of Personas in private windows.
+        let root = document.documentElement;
+
+        if (PrivateBrowsingUtils && PrivateBrowsingUtils.isWindowPrivate(window)
+                && root._lightweightTheme
+                && root._lightweightTheme._lastScreenWidth == null) {
+
+            let { isWindowPrivate } = PrivateBrowsingUtils;
+            try {
+                PrivateBrowsingUtils.isWindowPrivate = function () false;
+                let { LightweightThemeConsumer } = Cu.import("resource://gre/modules/LightweightThemeConsumer.jsm", {});
+                LightweightThemeConsumer.call(root._lightweightTheme, document);
+            }
+            catch (e) {
+                util.reportError(e);
+            }
+            finally {
+                PrivateBrowsingUtils.isWindowPrivate = isWindowPrivate;
+            }
+        }
+
         dactyl.timeout(function () {
             try {
                 var args = config.prefs.get("commandline-args")
diff --git a/common/modules/services.jsm b/common/modules/services.jsm
index e0bba764..d3ac781f 100644
--- a/common/modules/services.jsm
+++ b/common/modules/services.jsm
@@ -8,9 +8,14 @@ try {
 
 var global = this;
 defineModule("services", {
-    exports: ["services"]
+    exports: ["PrivateBrowsingUtils", "services"]
 });
 
+try {
+    var { PrivateBrowsingUtils } = Cu.import("resource://gre/modules/PrivateBrowsingUtils.jsm");
+}
+catch (e) {}
+
 /**
  * A lazily-instantiated XPCOM class and service cache.
  */
diff --git a/common/modules/storage.jsm b/common/modules/storage.jsm
index f4de771f..5bc7cada 100644
--- a/common/modules/storage.jsm
+++ b/common/modules/storage.jsm
@@ -167,8 +167,7 @@ var sessionGlobal = Cu.import("resource://gre/modules/Services.jsm", {})
 var Storage = Module("Storage", {
     Local: function Local(dactyl, modules, window) ({
         init: function init() {
-            this.privateMode = window.document.documentElement
-                                     .getAttribute("privatebrowsingmode");
+            this.privateMode = PrivateBrowsingUtils.isWindowPrivate(window);
         }
     }),