--- a/browser/base/content/browser.js
+++ b/browser/base/content/browser.js
@@ -3161,18 +3161,19 @@ const BrowserSearch = {
     // getSubmission can return null if the engine doesn't have a URL
     // with a text/html response type.  This is unlikely (since
     // SearchService._addEngineToStore() should fail for such an engine),
     // but let's be on the safe side.
     if (!submission)
       return;
   
     if (useNewTab) {
-      gBrowser.loadOneTab(submission.uri.spec, null, null,
-                          submission.postData, null, false);
+      gBrowser.loadOneTab(submission.uri.spec, {
+                          postData: submission.postData,
+                          relatedToCurrent: true});
     } else
       loadURI(submission.uri.spec, null, submission.postData, false);
   },
 
   /**
    * Returns the search bar element if it is present in the toolbar, null otherwise.
    */
   get searchBar() {