diff --git a/tests/kickscore-basics.rs b/tests/kickscore-basics.rs
index 0fd0956..8ca6887 100644
--- a/tests/kickscore-basics.rs
+++ b/tests/kickscore-basics.rs
@@ -8,13 +8,11 @@ fn kickscore_basic() {
     let mut model = ks::model::Binary::new(ks::model::binary::Observation::Probit);
 
     let k_spike = ks::kernel::Constant::new(0.5);
-
     let k_tom = ks::kernel::Exponential::new(1.0, 1.0);
-
-    let k_jerry: [Box<dyn ks::Kernel>; 2] = [
-        Box::new(ks::kernel::Constant::new(1.0)),
-        Box::new(ks::kernel::Matern52::new(0.5, 1.0)),
-    ];
+    let k_jerry = (
+        ks::kernel::Constant::new(1.0),
+        ks::kernel::Matern52::new(0.5, 1.0),
+    );
 
     model.add_item("Spike", k_spike);
     model.add_item("Tom", k_tom);
diff --git a/tests/nba-history.rs b/tests/nba-history.rs
index 112a7f1..de20909 100644
--- a/tests/nba-history.rs
+++ b/tests/nba-history.rs
@@ -61,10 +61,10 @@ fn nba_history() {
     let mut model = ks::model::Binary::new(ks::model::binary::Observation::Probit);
 
     for team in teams {
-        let kernel: [Box<dyn ks::Kernel>; 2] = [
-            Box::new(ks::kernel::Constant::new(0.03)),
-            Box::new(ks::kernel::Matern32::new(0.138, 1.753 * seconds_in_year)),
-        ];
+        let kernel = (
+            ks::kernel::Constant::new(0.03),
+            ks::kernel::Matern32::new(0.138, 1.753 * seconds_in_year),
+        );
 
         model.add_item(&team, kernel);
     }