diff --git a/Cargo.toml b/Cargo.toml
index 7f7d0a1..89d72cd 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,5 +1,6 @@
 [package]
 name = "downcast-rs"
+edition = "2015"
 version = "1.2.1"
 repository = "https://github.com/marcianx/downcast-rs"
 description = """
diff --git a/tests/import_via_macro_use.rs b/tests/import_via_macro_use.rs
index fc2fab2..2ee364b 100644
--- a/tests/import_via_macro_use.rs
+++ b/tests/import_via_macro_use.rs
@@ -4,6 +4,7 @@ extern crate downcast_rs;
 #[test]
 fn test() {
     use downcast_rs::Downcast;
+    #[allow(dead_code)]
     trait Trait: Downcast {}
     impl_downcast!(Trait);
 }
diff --git a/tests/use_via_namespace.rs b/tests/use_via_namespace.rs
index 19f630c..9d74c0c 100644
--- a/tests/use_via_namespace.rs
+++ b/tests/use_via_namespace.rs
@@ -3,6 +3,7 @@ extern crate downcast_rs;
 #[test]
 fn test() {
     use downcast_rs::Downcast;
+    #[allow(dead_code)]
     trait Trait: Downcast {}
     downcast_rs::impl_downcast!(Trait);
 }