android - how to remove ActionBarDivider in Holo theme

android - how to remove ActionBarDivider in Holo theme

I have an Activity with a dark ActionBar. I need to remove its vertical
dividers since my icons already have "built-in" dividers. What I've tried
goes below
Activity style:
<style name="sMain" parent="@android:style/Theme.Holo">
<item name="android:icon">@android:color/transparent</item>
<item name="android:actionBarStyle">@style/MyActionBar</item>
</style>
MyActionBar:
<style name="MyActionBar" parent="android:Widget.Holo.ActionBar">
<item name="android:actionBarDivider">@null</item>
</style>
This doesn't have any effect. Any ideas what I'm doing wrong?