I am a Delaware resident n my employer is in PA. my employer is withholding taxes for Delaware and PA. Any help on this how I can avoid getting double state taxed?

Hi All, I am a Delaware resident and my employer is in PA. I received my first pay and to my surprise my employer is withholding taxes for Delaware and PA. I am confused to why double withholdings for states since I am resident of Delaware. Any help on this how I can avoid getting double taxed?