How can I convert a Binding to a Binding?

Question

In my SwiftUI, I have the following:

struct PersonalDetailsView: View {
    // The profileStore manages user related data
    @EnvironmentObject var profileStore: ProfileStore

    var body: some View {
        DatePicker(selection: $profileStore.observedPerson.birthday,
                   in: ...Date(),
                   displayedComponents: [.date]) {
            Text("Birthday")
        }

        Picker("Weight", selection: $profileStore.observedPerson.weight) {
            ForEach(0 ..< 300) {
                Text("\($0) kg").foregroundColor(.gray)
            }
        }
    }
}

weight and birthday are both optionals. In the normal Picker I don't get any error, but in the DatePicker I get the following:

Cannot convert value of type 'Binding< Date? >' to expected argument type 'Binding< Date >'

How can I fix this? If you need further information about profileStore or observedPerson, just comment.