--- a/browser/base/content/test/general/browser_contentSearchUI.js
+++ b/browser/base/content/test/general/browser_contentSearchUI.js
@@ -709,21 +709,20 @@ function checkState(actualState, expecte
     expectedState.selectedButtonIndex = expectedSelectedIdx - expectedSuggestions.length;
   }
 
   SimpleTest.isDeeply(actualState, expectedState, "State");
 }
 
 var gMsgMan;
 
-function promiseTab() {
+function* promiseTab() {
   let deferred = Promise.defer();
-  let tab = gBrowser.addTab();
-  registerCleanupFunction(() => gBrowser.removeTab(tab));
-  gBrowser.selectedTab = tab;
+  let tab = yield BrowserTestUtils.openNewForegroundTab(gBrowser);
+  registerCleanupFunction(() => BrowserTestUtils.removeTab(tab));
   let pageURL = getRootDirectory(gTestPath) + TEST_PAGE_BASENAME;
   tab.linkedBrowser.addEventListener("load", function onLoad(event) {
     tab.linkedBrowser.removeEventListener("load", onLoad, true);
     gMsgMan = tab.linkedBrowser.messageManager;
     gMsgMan.sendAsyncMessage("ContentSearch", {
       type: "AddToWhitelist",
       data: [pageURL],
     });