--- a/browser/base/content/tabview/ui.js
+++ b/browser/base/content/tabview/ui.js
@@ -709,19 +709,19 @@ let UI = {
         // If we're currently in the process of entering private browsing,
         // we don't want to go to the Tab View UI. 
         if (self._privateBrowsing.transitionMode)
           return; 
           
         // if not closing the last tab
         if (gBrowser.tabs.length > 1) {
           // Don't return to TabView if there are any app tabs
-          for (let a = 0; a < gBrowser.tabs.length; a++) {
+          for (let a = 0; a < gBrowser._numPinnedTabs; a++) {
             let theTab = gBrowser.tabs[a]; 
-            if (theTab.pinned && gBrowser._removingTabs.indexOf(theTab) == -1) 
+            if (gBrowser._removingTabs.indexOf(theTab) == -1) 
               return;
           }
 
           var groupItem = GroupItems.getActiveGroupItem();
 
           // 1) Only go back to the TabView tab when there you close the last
           // tab of a groupItem.
           let closingLastOfGroup = (groupItem &&