diff --git a/atom/browser/api/atom_api_menu.h b/atom/browser/api/atom_api_menu.h
index d345262810..1ea83653e7 100644
--- a/atom/browser/api/atom_api_menu.h
+++ b/atom/browser/api/atom_api_menu.h
@@ -52,8 +52,9 @@ class Menu : public mate::TrackableObject<Menu>,
   void MenuWillShow(ui::SimpleMenuModel* source) override;
 
   virtual void Popup(Window* window) = 0;
-  virtual void PopupAt(Window* window, int x, int y,
-      int positioningItem = 0) = 0;
+  virtual void PopupAt(Window* window,
+                       int x = -1, int y = -1,
+                       int positioning_item = 0) = 0;
 
   scoped_ptr<AtomMenuModel> model_;
   Menu* parent_;
diff --git a/atom/browser/api/atom_api_menu_mac.h b/atom/browser/api/atom_api_menu_mac.h
index e71198315b..34450bc8b5 100644
--- a/atom/browser/api/atom_api_menu_mac.h
+++ b/atom/browser/api/atom_api_menu_mac.h
@@ -20,7 +20,7 @@ class MenuMac : public Menu {
   MenuMac();
 
   void Popup(Window* window) override;
-  void PopupAt(Window* window, int x, int y, int positioningItem = 0) override;
+  void PopupAt(Window* window, int x, int y, int positioning_item = 0) override;
 
   base::scoped_nsobject<AtomMenuController> menu_controller_;
 
diff --git a/atom/browser/api/atom_api_menu_mac.mm b/atom/browser/api/atom_api_menu_mac.mm
index 7e505ccd9d..d87617a5fc 100644
--- a/atom/browser/api/atom_api_menu_mac.mm
+++ b/atom/browser/api/atom_api_menu_mac.mm
@@ -50,7 +50,7 @@ void MenuMac::Popup(Window* window) {
                    forView:web_contents->GetContentNativeView()];
 }
 
-void MenuMac::PopupAt(Window* window, int x, int y, int positioningItem) {
+void MenuMac::PopupAt(Window* window, int x, int y, int positioning_item) {
   NativeWindow* native_window = window->window();
   if (!native_window)
     return;
@@ -64,13 +64,13 @@ void MenuMac::PopupAt(Window* window, int x, int y, int positioningItem) {
   NSView* view = web_contents->GetContentNativeView();
 
   // Show the menu.
-  if (positioningItem >= [menu numberOfItems]) {
-    positioningItem = [menu numberOfItems] - 1;
+  if (positioning_item >= [menu numberOfItems]) {
+    positioning_item = [menu numberOfItems] - 1;
   }
-  if (positioningItem < 0) {
-    positioningItem = 0;
+  if (positioning_item < 0) {
+    positioning_item = 0;
   }
-  [menu popUpMenuPositioningItem:[menu itemAtIndex:positioningItem]
+  [menu popUpMenupositioning_item:[menu itemAtIndex:positioning_item]
                       atLocation:NSMakePoint(x, [view frame].size.height - y)
                           inView:view];
 }
diff --git a/atom/browser/api/atom_api_menu_views.cc b/atom/browser/api/atom_api_menu_views.cc
index 67b55d5e98..93869df87f 100644
--- a/atom/browser/api/atom_api_menu_views.cc
+++ b/atom/browser/api/atom_api_menu_views.cc
@@ -20,7 +20,7 @@ void MenuViews::Popup(Window* window) {
   PopupAtPoint(window, gfx::Screen::GetNativeScreen()->GetCursorScreenPoint());
 }
 
-void MenuViews::PopupAt(Window* window, int x, int y, int positioningItem) {
+void MenuViews::PopupAt(Window* window, int x, int y, int positioning_item) {
   NativeWindow* native_window = static_cast<NativeWindow*>(window->window());
   if (!native_window)
     return;
diff --git a/atom/browser/api/atom_api_menu_views.h b/atom/browser/api/atom_api_menu_views.h
index 9e306b4e72..9f1b116a00 100644
--- a/atom/browser/api/atom_api_menu_views.h
+++ b/atom/browser/api/atom_api_menu_views.h
@@ -18,7 +18,7 @@ class MenuViews : public Menu {
 
  protected:
   void Popup(Window* window) override;
-  void PopupAt(Window* window, int x, int y, int positioningItem = 0) override;
+  void PopupAt(Window* window, int x, int y, int positioning_item = 0) override;
 
  private:
   void PopupAtPoint(Window* window, const gfx::Point& point);