My bash prompt is not working in `screen`

On RedHat, screen resets my bash prompt. I set PS1=\u@\h:\w in ~/.bashrc and ~/.bash_profile. I added shell -$SHELL as well to ~/.screenrc. But, when I open a brand new terminal window, the prompt is correct, except in screen. In screen I always get this prompt format: \u@\h> How can I set the same prompt in screen?