diff --git a/layout/xul/nsMenuBarListener.cpp b/layout/xul/nsMenuBarListener.cpp
index a4ee19638035..a49e2eb53516 100644
--- a/layout/xul/nsMenuBarListener.cpp
+++ b/layout/xul/nsMenuBarListener.cpp
@@ -313,7 +313,7 @@ nsMenuBarListener::KeyPress(nsIDOMEvent* aKeyEvent)
         if (mMenuBarFrame->IsActive()) {
 #ifdef MOZ_WIDGET_GTK
           // In GTK, this also opens the first menu.
-          mMenuBarFrame->GetCurrentMenuItem()->OpenMenu(true);
+          mMenuBarFrame->GetCurrentMenuItem()->OpenMenu(false);
 #endif
           aKeyEvent->StopPropagation();
           aKeyEvent->PreventDefault();
diff --git a/layout/xul/nsXULPopupManager.cpp b/layout/xul/nsXULPopupManager.cpp
index dc25f7c69af2..81d76352d412 100644
--- a/layout/xul/nsXULPopupManager.cpp
+++ b/layout/xul/nsXULPopupManager.cpp
@@ -2193,6 +2193,21 @@ nsXULPopupManager::HandleKeyboardNavigation(uint32_t aKeyCode)
                  aKeyCode <= nsIDOMKeyEvent::DOM_VK_DOWN, "Illegal key code");
   theDirection = NS_DIRECTION_FROM_KEY_CODE(itemFrame, aKeyCode);
 
+  bool selectFirstItem = true;
+#ifdef MOZ_WIDGET_GTK
+  nsMenuFrame* currentItem = nullptr;
+  if (item && mActiveMenuBar && NS_DIRECTION_IS_INLINE(theDirection)) {
+    currentItem = item->Frame()->GetCurrentMenuItem();
+    // If nothing is selected in the menu and we have a menubar, let it
+    // handle the movement not to steal focus from it.
+    if (!currentItem) {
+      item = nullptr;
+    }
+  }
+  // On menu change, only select first item if an item is already selected.
+  selectFirstItem = currentItem != nullptr;
+#endif
+
   // if a popup is open, first check for navigation within the popup
   if (item && HandleKeyboardNavigationInPopup(item, theDirection))
     return true;
@@ -2205,7 +2220,7 @@ nsXULPopupManager::HandleKeyboardNavigation(uint32_t aKeyCode)
       nsMenuFrame* nextItem = (theDirection == eNavigationDirection_End) ?
                               GetNextMenuItem(mActiveMenuBar, currentMenu, false, true) :
                               GetPreviousMenuItem(mActiveMenuBar, currentMenu, false, true);
-      mActiveMenuBar->ChangeMenuItem(nextItem, true, true);
+      mActiveMenuBar->ChangeMenuItem(nextItem, selectFirstItem, true);
       return true;
     }
     else if (NS_DIRECTION_IS_BLOCK(theDirection)) {
diff --git a/toolkit/content/tests/widgets/window_menubar.xul b/toolkit/content/tests/widgets/window_menubar.xul
index b7669e0b37bd..1acb4266b752 100644
--- a/toolkit/content/tests/widgets/window_menubar.xul
+++ b/toolkit/content/tests/widgets/window_menubar.xul
@@ -95,14 +95,14 @@ window.opener.SimpleTest.waitForFocus(function () {
 function pressF10Events()
 {
   return navigator.platform.indexOf("Linux") >= 0 ?
-    [ "DOMMenuBarActive menubar", "DOMMenuItemActive filemenu", "popupshowing filepopup", "DOMMenuItemActive item1", "popupshown filepopup"] :
+    [ "DOMMenuBarActive menubar", "DOMMenuItemActive filemenu", "popupshowing filepopup", "popupshown filepopup"] :
     [ "DOMMenuBarActive menubar", "DOMMenuItemActive filemenu" ];
 }
 
 function closeAfterF10Events(extraInactive)
 {
   if (navigator.platform.indexOf("Linux") >= 0) {
-    var events = [ "popuphiding filepopup", "popuphidden filepopup", "DOMMenuItemInactive item1",
+    var events = [ "popuphiding filepopup", "popuphidden filepopup",
                    "DOMMenuInactive filepopup", "DOMMenuBarInactive menubar",
                    "DOMMenuItemInactive filemenu" ];
     if (extraInactive)
@@ -479,9 +479,9 @@ var popupTests = [
                // "accelerator on active menubar" because menus opened from a
                // shortcut key are fired asynchronously
                "popuphiding filepopup", "popuphidden filepopup",
-               "popupshowing helppopup", "DOMMenuItemInactive item1",
-               "DOMMenuItemActive item2", "DOMMenuItemInactive item2",
-               "DOMMenuInactive filepopup", "DOMMenuItemActive contents",
+               "popupshowing helppopup",
+               "DOMMenuItemActive item1", "DOMMenuItemInactive item1",
+               "DOMMenuInactive filepopup",
                "popupshown helppopup" ] :
             [ "popupshowing helppopup", "DOMMenuItemInactive filemenu",
               "DOMMenuItemActive helpmenu",
@@ -499,7 +499,9 @@ var popupTests = [
   // should not close because there is more than one item corresponding to
   // that letter
   testname: "menuitem with no accelerator",
-  events: [ "DOMMenuItemInactive contents", "DOMMenuItemActive one" ],
+  events: (navigator.platform.indexOf("Linux") >= 0) ?
+           [ "DOMMenuItemActive one" ] :
+           [ "DOMMenuItemInactive contents", "DOMMenuItemActive one" ],
   test: function() { sendChar("o"); },
   result: function(testname) { checkOpen("helpmenu", testname); }
 },