diff --git a/tests/no_send_sync.rs b/tests/no_send_sync.rs
index 1bc14a05..ac919672 100644
--- a/tests/no_send_sync.rs
+++ b/tests/no_send_sync.rs
@@ -1,4 +1,3 @@
-#[macro_use]
 extern crate salsa;
 
 use std::rc::Rc;
@@ -9,11 +8,11 @@ trait NoSendSyncDatabase: salsa::Database {
     fn no_send_sync_key(&self, key: Rc<bool>) -> bool;
 }
 
-fn no_send_sync_value(db: &impl NoSendSyncDatabase, key: bool) -> Rc<bool> {
+fn no_send_sync_value(_db: &impl NoSendSyncDatabase, key: bool) -> Rc<bool> {
     Rc::new(key)
 }
 
-fn no_send_sync_key(db: &impl NoSendSyncDatabase, key: Rc<bool>) -> bool {
+fn no_send_sync_key(_db: &impl NoSendSyncDatabase, key: Rc<bool>) -> bool {
     *key
 }
 
@@ -31,7 +30,7 @@ impl salsa::Database for DatabaseImpl {
 
 #[test]
 fn no_send_sync() {
-    let mut db = DatabaseImpl::default();
+    let db = DatabaseImpl::default();
 
     assert_eq!(db.no_send_sync_value(true), Rc::new(true));
     assert_eq!(db.no_send_sync_key(Rc::new(false)), false);