If the sauce is still too thin, slowly add more corn starch, stirring, until it reaches the desired thickness. (fieryfoodscentral.com)
I also added a bit more corn starch because I'm used to it being thicker, because that's the way my dad made it when i was growing up. (thecrepesofwrath.com)
If you are out of potato starch use more corn starch or tapioca starch instead. (eatthelove.com)