diff --git a/app/sync.js b/app/sync.js
index 026fd61137d..69496417c71 100644
--- a/app/sync.js
+++ b/app/sync.js
@@ -176,6 +176,7 @@ module.exports.onSyncReady = (isFirstRun, e) => {
   }
   const appState = AppStore.getState()
   const sites = appState.get('sites') || new Immutable.List()
+  const seed = appState.get('seed') || new Immutable.List()
 
   /**
    * Sync a bookmark that has not been synced yet, first syncing the parent
@@ -187,7 +188,8 @@ module.exports.onSyncReady = (isFirstRun, e) => {
    */
   const folderToObjectId = {}
   const syncBookmark = (site) => {
-    if (!site || site.get('objectId') || folderToObjectId[site.get('folderId')] || !syncUtil.isSyncable('bookmark', site)) {
+    if (!site || (site.get('objectId') && seed.equals(site.get('originalSeed'))) ||
+      folderToObjectId[site.get('folderId')] || !syncUtil.isSyncable('bookmark', site)) {
       return
     }
 
diff --git a/docs/state.md b/docs/state.md
index c56db050cdd..5c0caf1f89b 100644
--- a/docs/state.md
+++ b/docs/state.md
@@ -224,6 +224,7 @@ AppStore
       lastAccessedTime: number, // datetime.getTime()
       location: string,
       objectId: Array.<number>,
+      originalSeed: Array.<number>, // only set for bookmarks that have been synced before a sync profile reset
       parentFolderId: number, // set for bookmarks and bookmark folders only
       partitionNumber: number, // optionally specifies a specific session
       tags: [string], // empty, 'bookmark', 'bookmark-folder', 'pinned', or 'reader'
diff --git a/js/stores/appStore.js b/js/stores/appStore.js
index 4e6af56a2b7..4e191e09793 100644
--- a/js/stores/appStore.js
+++ b/js/stores/appStore.js
@@ -941,14 +941,16 @@ const handleAppAction = (action) => {
     case appConstants.APP_RESET_SYNC_DATA:
       const sessionStore = require('../../app/sessionStore')
       const syncDefault = Immutable.fromJS(sessionStore.defaultAppState().sync)
+      const originalSeed = appState.getIn(['sync', 'seed'])
       appState = appState.set('sync', syncDefault)
       appState.get('sites').forEach((site, key) => {
-        if (!site.has('objectId')) { return }
-        appState = appState.setIn(['sites', key], site.delete('objectId'))
-      })
-      appState.get('siteSettings').forEach((site, key) => {
-        if (!site.has('objectId')) { return }
-        appState = appState.setIn(['siteSettings', key], site.delete('objectId'))
+        if (site.has('objectId') && syncUtil.isSyncable('bookmark', site)) {
+          // Remember which profile this bookmark was originally synced to.
+          // Since old bookmarks should be synced when a new profile is created,
+          // we have to keep track of which profile already has these bookmarks
+          // or else the old profile may have these bookmarks duplicated. #7405
+          appState = appState.setIn(['sites', key, 'originalSeed'], originalSeed)
+        }
       })
       break
     case appConstants.APP_SHOW_DOWNLOAD_DELETE_CONFIRMATION: