diff --git a/widget/src/gtk2/nsNativeThemeGTK.cpp b/widget/src/gtk2/nsNativeThemeGTK.cpp
index 5893aadc050..f6a3d69a9ca 100644
--- a/widget/src/gtk2/nsNativeThemeGTK.cpp
+++ b/widget/src/gtk2/nsNativeThemeGTK.cpp
@@ -960,6 +960,7 @@ nsNativeThemeGTK::ThemeSupportsWidget(nsPresContext* aPresContext,
   case NS_THEME_SPINNER_UP_BUTTON:
   case NS_THEME_SPINNER_DOWN_BUTTON:
     // case NS_THEME_SCROLLBAR:  (n/a for gtk)
+    // case NS_THEME_SCROLLBAR_SMALL: (n/a for gtk)
   case NS_THEME_SCROLLBAR_BUTTON_UP:
   case NS_THEME_SCROLLBAR_BUTTON_DOWN:
   case NS_THEME_SCROLLBAR_BUTTON_LEFT:
diff --git a/widget/src/windows/nsNativeThemeWin.cpp b/widget/src/windows/nsNativeThemeWin.cpp
index b0011188a23..4c60dcb80e9 100644
--- a/widget/src/windows/nsNativeThemeWin.cpp
+++ b/widget/src/windows/nsNativeThemeWin.cpp
@@ -322,6 +322,7 @@ nsNativeThemeWin::GetTheme(PRUint8 aWidgetType)
       return mTabTheme;
     }
     case NS_THEME_SCROLLBAR:
+    case NS_THEME_SCROLLBAR_SMALL:
     case NS_THEME_SCROLLBAR_TRACK_VERTICAL:
     case NS_THEME_SCROLLBAR_TRACK_HORIZONTAL:
     case NS_THEME_SCROLLBAR_BUTTON_UP:
@@ -683,7 +684,8 @@ nsNativeThemeWin::GetThemePartAndState(nsIFrame* aFrame, PRUint8 aWidgetType,
     }
     case NS_THEME_TOOLBOX:
     case NS_THEME_STATUSBAR:
-    case NS_THEME_SCROLLBAR: {
+    case NS_THEME_SCROLLBAR:
+    case NS_THEME_SCROLLBAR_SMALL: {
       aPart = aState = 0;
       return NS_OK; // These have no part or state.
     }