--- a/browser/base/content/test/social/browser_social_perwindowPB.js
+++ b/browser/base/content/test/social/browser_social_perwindowPB.js
@@ -33,17 +33,19 @@ function postAndReceive(port, postTopic,
 
 function test() {
   waitForExplicitFinish();
 
   let manifest = { // normal provider
     name: "provider 1",
     origin: "https://example.com",
     sidebarURL: "https://example.com/browser/browser/base/content/test/social/social_sidebar.html",
+    statusURL: "https://example.com/browser/browser/base/content/test/social/social_panel.html",
     workerURL: "https://example.com/browser/browser/base/content/test/social/social_worker.js",
+    markURL: "https://example.com/browser/browser/base/content/test/social/social_mark.html?url=%{url}",
     iconURL: "https://example.com/browser/browser/base/content/test/general/moz.png"
   };
   runSocialTestWithProvider(manifest, function (finishcb) {
     openTab(window, "http://example.com", function(newTab) {
       runSocialTests(tests, undefined, undefined, function() {
         window.gBrowser.removeTab(newTab);
         finishcb();
       });
@@ -63,20 +65,36 @@ var tests = {
       // open a new private-window
       openPBWindow(function(pbwin) {
         // The provider should remain alive.
         postAndReceive(port, "ping", "pong", function() {
           // the new window should have no social features at all.
           info("checking private window ui");
           ok(!pbwin.SocialUI.enabled, "social is disabled in a PB window");
           checkSocialUI(pbwin);
+
           // but they should all remain enabled in the initial window
           info("checking main window ui");
           ok(window.SocialUI.enabled, "social is still enabled in normal window");
           checkSocialUI(window);
+
+          // Check that the status button is disabled on the private
+          // browsing window and not on the normal window.
+          let id = SocialStatus._toolbarHelper.idFromOrigin("https://example.com");
+          let widget = CustomizableUI.getWidget(id);
+          ok(widget.forWindow(pbwin).node.disabled, "status button disabled on private window");
+          ok(!widget.forWindow(window).node.disabled, "status button enabled on normal window");
+
+          // Check that the mark button is disabled on the private
+          // browsing window and not on the normal window.
+          id = SocialMarks._toolbarHelper.idFromOrigin("https://example.com");
+          widget = CustomizableUI.getWidget(id);
+          ok(widget.forWindow(pbwin).node.disabled, "mark button disabled on private window");
+          ok(!widget.forWindow(window).node.disabled, "mark button enabled on normal window");
+
           // that's all folks...
           pbwin.close();
           next();
         })
       });
     });
   },
 }

--- a/browser/modules/Social.jsm
+++ b/browser/modules/Social.jsm
@@ -20,16 +20,18 @@ Cu.import("resource://gre/modules/Servic
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 
 XPCOMUtils.defineLazyModuleGetter(this, "CustomizableUI",
   "resource:///modules/CustomizableUI.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "SocialService",
   "resource://gre/modules/SocialService.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "PlacesUtils",
   "resource://gre/modules/PlacesUtils.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "PrivateBrowsingUtils",
+  "resource://gre/modules/PrivateBrowsingUtils.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "Promise",
   "resource://gre/modules/Promise.jsm");
 
 XPCOMUtils.defineLazyServiceGetter(this, "unescapeService",
                                    "@mozilla.org/feed-unescapehtml;1",
                                    "nsIScriptableUnescapeHTML");
 
 // Add a pref observer for the enabled state
@@ -393,16 +395,19 @@ function CreateSocialStatusWidget(aId, a
       node.setAttribute('class', 'toolbarbutton-1 chromeclass-toolbar-additional social-status-button');
       node.setAttribute('type', "badged");
       node.style.listStyleImage = "url(" + (aProvider.icon32URL || aProvider.iconURL) + ")";
       node.setAttribute("origin", aProvider.origin);
       node.setAttribute("label", aProvider.name);
       node.setAttribute("tooltiptext", aProvider.name);
       node.setAttribute("oncommand", "SocialStatus.showPopup(this);");
 
+      if (PrivateBrowsingUtils.isWindowPrivate(aDocument.defaultView))
+        node.setAttribute("disabled", "true");
+
       return node;
     }
   });
 };
 
 function CreateSocialMarkWidget(aId, aProvider) {
   if (!aProvider.markURL)
     return;