Undefined variable: sb

I get this error when I turn on all warnings for PHP.
Notice: Undefined variable: sb in /wp-content/plugins/custom-sidebars/customsidebars.php on line 98

This line reads:
if($this->checkAndFixSidebar($sb, $replacement, $replacement_type, $extra_index)){

I changed it to:
if($this->checkAndFixSidebar($sb_name, $replacement, $replacement_type, $extra_index)){

Is this correct change? Can this be fixed in the next release?

https://www.ads-software.com/extend/plugins/custom-sidebars/