diff --git a/src/lib.rs b/src/lib.rs
index b74d51f..c766b73 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -58,7 +58,7 @@ pub trait Backend {
     fn set_volume(&mut self, volume: u8) -> Result<(), Error>;
 }
 
-pub struct TTS(Box<Backend>);
+pub struct TTS(Box<dyn Backend>);
 
 unsafe impl std::marker::Send for TTS {}