diff --git a/src/system.rs b/src/system.rs
index 2676f1b..16ea33a 100644
--- a/src/system.rs
+++ b/src/system.rs
@@ -119,6 +119,7 @@ pub(crate) trait SystemParam {
         arguments: &'r [&'r str],
         factory: &'r Factory,
     ) -> Self::Item<'r>;
+    #[allow(unused_variables)]
     fn valid(prefix: &IrcPrefix, arguments: &[&str], factory: &Factory) -> bool {
         true
     }
diff --git a/src/system_params.rs b/src/system_params.rs
index 21fae85..be101cf 100644
--- a/src/system_params.rs
+++ b/src/system_params.rs
@@ -129,9 +129,7 @@ impl<'a, const N: usize> SystemParam for Arguments<'a, N> {
         Arguments(&arguments[..N])
     }
 
-    fn valid(_prefix: &IrcPrefix,
-    arguments: &[&str],
-    _factory: &Factory,) -> bool {
+    fn valid(_prefix: &IrcPrefix, arguments: &[&str], _factory: &Factory) -> bool {
         arguments.len() == N
     }
 }