diff --git a/embassy-executor/src/lib.rs b/embassy-executor/src/lib.rs
index 70abfcc3a..e26e8ee7d 100644
--- a/embassy-executor/src/lib.rs
+++ b/embassy-executor/src/lib.rs
@@ -70,7 +70,7 @@ pub mod _export {
     impl TaskReturnValue for Never {}
 
     #[diagnostic::on_unimplemented(
-        message = "task function futures must resolve to `()`",
+        message = "task futures must resolve to `()` or `!`",
         note = "use `async fn` or change the return type to `impl Future<Output = ()>`"
     )]
     #[allow(private_bounds)]