Main.hx:5: lines 5-7 : Field test has different type than in I Main.hx:16: characters 2-32 : Interface field is defined here Main.hx:5: lines 5-7 : error: String should be Dynamic Main.hx:5: lines 5-7 : have: (Dynamic) -> ... Main.hx:5: lines 5-7 : want: (String) -> ...