diff --git a/mozilla/browser/base/content/browser.js b/mozilla/browser/base/content/browser.js
index ef377db1eac..867bf2a5f8b 100644
--- a/mozilla/browser/base/content/browser.js
+++ b/mozilla/browser/base/content/browser.js
@@ -2759,8 +2759,8 @@ function FillHistoryMenu(aParent, aMenu)
             }
           break;
         case "forward":
-          end  = ((count-index) > MAX_HISTORY_MENU_ITEMS) ? index + MAX_HISTORY_MENU_ITEMS : count;
-          if ((index + 1) >= end) return false;
+          end  = ((count-index) > MAX_HISTORY_MENU_ITEMS) ? index + MAX_HISTORY_MENU_ITEMS : count - 1;
+          if ((index + 1) > end) return false;
           for (j = index + 1; j <= end; j++)
             {
               entry = sessionHistory.getEntryAtIndex(j, false);
diff --git a/mozilla/toolkit/components/help/content/help.js b/mozilla/toolkit/components/help/content/help.js
index 59c3fc31409..2e3d91e4eea 100644
--- a/mozilla/toolkit/components/help/content/help.js
+++ b/mozilla/toolkit/components/help/content/help.js
@@ -457,8 +457,8 @@ function FillHistoryMenu(aParent, aMenu)
             }
           break;
         case "forward":
-          end  = ((count-index) > MAX_HISTORY_MENU_ITEMS) ? index + MAX_HISTORY_MENU_ITEMS : count;
-          if ((index + 1) >= end) return false;
+          end  = ((count-index) > MAX_HISTORY_MENU_ITEMS) ? index + MAX_HISTORY_MENU_ITEMS : count - 1;
+          if ((index + 1) > end) return false;
           for (j = index + 1; j <= end; j++)
             {
               entry = sessionHistory.getEntryAtIndex(j, false);