1 files changed, 1 insertions, 1 deletions
diff --git a/src/lib.rs b/src/lib.rs
index 1bcdada2..da108804 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -5,7 +5,7 @@ mod platform;
 pub use platform::*;
 
 pub trait Application {
-    type Message;
+    type Message: std::fmt::Debug;
 
     fn update(&mut self, message: Self::Message);