diff --git a/tests/sum.rs b/tests/sum.rs
index a273bf80..503d6b4f 100644
--- a/tests/sum.rs
+++ b/tests/sum.rs
@@ -1,4 +1,5 @@
 #![cfg_attr(not(feature = "std"), no_std)]
+#![allow(dead_code)] // some code is tested for type checking only
 
 use derive_more::Sum;