Sustain Pedal in Built in Playback?

Hello I'm using a midi keyboard for note input when I arrange/compose.
The way I figure out what to write is by improvising on the piano.
For that, I rely heavily on the built-in playback; I use it like a DAW.
Well, the only problem is that the sustain pedal connected to the keyboard is not working with Musescore.
Any fix for this?