--- a/services/sync/modules/engines/bookmarks.js
+++ b/services/sync/modules/engines/bookmarks.js
@@ -1319,17 +1319,25 @@ BookmarksStore.prototype = {
     PlacesUtils.tagging.tagURI(dummyURI, tags);
     PlacesUtils.tagging.untagURI(bookmarkURI, null);
     PlacesUtils.tagging.tagURI(bookmarkURI, tags);
     PlacesUtils.tagging.untagURI(dummyURI, null);
   },
 
   getAllIDs: function BStore_getAllIDs() {
     let items = {"menu": true,
-                 "toolbar": true};
+                 "toolbar": true,
+                 "unfiled": true,
+                };
+    // We also want "mobile" but only if a local mobile folder already exists
+    // (otherwise we'll later end up creating it, which we want to avoid until
+    // we actually need it.)
+    if (kSpecialIds.findMobileRoot(false)) {
+      items["mobile"] = true;
+    }
     for each (let guid in kSpecialIds.guids) {
       if (guid != "places" && guid != "tags")
         this._getChildren(guid, items);
     }
     return items;
   },
 
   wipe: function BStore_wipe() {

--- a/services/sync/tests/unit/test_bookmark_engine.js
+++ b/services/sync/tests/unit/test_bookmark_engine.js
@@ -222,17 +222,17 @@ add_task(function test_restorePromptsReu
       error = ex;
       _("Got error: " + Utils.exceptionStr(ex));
     }
     do_check_true(!error);
 
     _("Verify that there's only one bookmark on the server, and it's Thunderbird.");
     // Of course, there's also the Bookmarks Toolbar and Bookmarks Menu...
     let wbos = collection.keys(function (id) {
-      return ["menu", "toolbar", "mobile", folder1_guid].indexOf(id) == -1;
+      return ["menu", "toolbar", "mobile", "unfiled", folder1_guid].indexOf(id) == -1;
     });
     do_check_eq(wbos.length, 1);
     do_check_eq(wbos[0], bmk2_guid);
 
     _("Now restore from a backup.");
     yield BookmarkJSONUtils.importFromFile(backupFile, true);
 
     _("Ensure we have the bookmarks we expect locally.");
@@ -252,17 +252,17 @@ add_task(function test_restorePromptsReu
         newFX = guid;   // Save the new GUID after restore.
         found = true;   // Only runs if the above check passes.
       }
     }
     _("We found it: " + found);
     do_check_true(found);
 
     _("Have the correct number of IDs locally, too.");
-    do_check_eq(count, ["menu", "toolbar", folder1_id, bmk1_id].length);
+    do_check_eq(count, ["menu", "toolbar", "mobile", "unfiled", folder1_id, bmk1_id].length);
 
     _("Sync again. This'll wipe bookmarks from the server.");
     try {
       engine.sync();
     } catch(ex) {
       error = ex;
       _("Got error: " + Utils.exceptionStr(ex));
     }
@@ -272,17 +272,19 @@ add_task(function test_restorePromptsReu
     // Of course, there's also the Bookmarks Toolbar and Bookmarks Menu...
     let payloads     = server.user("foo").collection("bookmarks").payloads();
     let bookmarkWBOs = payloads.filter(function (wbo) {
                          return wbo.type == "bookmark";
                        });
     let folderWBOs   = payloads.filter(function (wbo) {
                          return ((wbo.type == "folder") &&
                                  (wbo.id   != "menu") &&
-                                 (wbo.id   != "toolbar"));
+                                 (wbo.id   != "toolbar") &&
+                                 (wbo.id   != "unfiled") &&
+                                 (wbo.id   != "mobile"));
                        });
 
     do_check_eq(bookmarkWBOs.length, 1);
     do_check_eq(bookmarkWBOs[0].id, newFX);
     do_check_eq(bookmarkWBOs[0].bmkUri, fxuri.spec);
     do_check_eq(bookmarkWBOs[0].title, "Get Firefox!");
 
     _("Our old friend Folder 1 is still in play.");

--- a/services/sync/tests/unit/test_bookmark_smart_bookmarks.js
+++ b/services/sync/tests/unit/test_bookmark_smart_bookmarks.js
@@ -107,17 +107,17 @@ add_test(function test_annotation_upload
   do_check_eq(smartBookmarkCount(), startCount + 1);
 
   _("Sync record to the server.");
   let collection = server.user("foo").collection("bookmarks");
 
   try {
     engine.sync();
     let wbos = collection.keys(function (id) {
-                 return ["menu", "toolbar", "mobile"].indexOf(id) == -1;
+                 return ["menu", "toolbar", "mobile", "unfiled"].indexOf(id) == -1;
                });
     do_check_eq(wbos.length, 1);
 
     _("Verify that the server WBO has the annotation.");
     let serverGUID = wbos[0];
     do_check_eq(serverGUID, guid);
     let serverWBO = collection.wbo(serverGUID);
     do_check_true(!!serverWBO);