diff --git a/tests/DataTableAppendColumns.test.svelte b/tests/DataTableAppendColumns.test.svelte
index 724e394a..682509dd 100644
--- a/tests/DataTableAppendColumns.test.svelte
+++ b/tests/DataTableAppendColumns.test.svelte
@@ -6,19 +6,59 @@
     { key: "port", value: "Port" },
     { key: "rule", value: "Rule" },
     { key: "overflow", empty: true },
-  ];
+  ] as const;
 
   const rows = [
-    { id: "a", name: "Load Balancer 3", port: 3000, rule: "Round robin" },
-    { id: "b", name: "Load Balancer 1", port: 443, rule: "Round robin" },
-    { id: "c", name: "Load Balancer 2", port: 80, rule: "DNS delegation" },
-    { id: "d", name: "Load Balancer 6", port: 3000, rule: "Round robin" },
-    { id: "e", name: "Load Balancer 4", port: 443, rule: "Round robin" },
-    { id: "f", name: "Load Balancer 5", port: 80, rule: "DNS delegation" },
+    {
+      id: "a",
+      name: "Load Balancer 3",
+      port: 3000,
+      rule: "Round robin",
+      overflow: null,
+    },
+    {
+      id: "b",
+      name: "Load Balancer 1",
+      port: 443,
+      rule: "Round robin",
+      overflow: null,
+    },
+    {
+      id: "c",
+      name: "Load Balancer 2",
+      port: 80,
+      rule: "DNS delegation",
+      overflow: null,
+    },
+    {
+      id: "d",
+      name: "Load Balancer 6",
+      port: 3000,
+      rule: "Round robin",
+      overflow: null,
+    },
+    {
+      id: "e",
+      name: "Load Balancer 4",
+      port: 443,
+      rule: "Round robin",
+      overflow: null,
+    },
+    {
+      id: "f",
+      name: "Load Balancer 5",
+      port: 80,
+      rule: "DNS delegation",
+      overflow: null,
+    },
   ];
 </script>
 
-<DataTable sortable headers="{headers}" rows="{rows}">
+<DataTable
+  sortable
+  headers="{headers}"
+  rows="{rows}"
+>
   <span slot="cell" let:cell>
     {#if cell.key === "overflow"}
       <OverflowMenu flipped>
diff --git a/tests/DataTableBatchSelection.test.svelte b/tests/DataTableBatchSelection.test.svelte
index 69c7ea16..0408974d 100644
--- a/tests/DataTableBatchSelection.test.svelte
+++ b/tests/DataTableBatchSelection.test.svelte
@@ -5,7 +5,7 @@
     { key: "name", value: "Name" },
     { key: "port", value: "Port" },
     { key: "rule", value: "Rule" },
-  ];
+  ] as const;
 
   const rows = [
     { id: "a", name: "Load Balancer 3", port: 3000, rule: "Round robin" },
diff --git a/tests/DataTableBatchSelectionToolbar.test.svelte b/tests/DataTableBatchSelectionToolbar.test.svelte
index 88336de3..2e98eb9b 100644
--- a/tests/DataTableBatchSelectionToolbar.test.svelte
+++ b/tests/DataTableBatchSelectionToolbar.test.svelte
@@ -15,7 +15,7 @@
     { key: "name", value: "Name" },
     { key: "port", value: "Port" },
     { key: "rule", value: "Rule" },
-  ];
+  ] as const;
 
   const rows = [
     { id: "a", name: "Load Balancer 3", port: 3000, rule: "Round robin" },
diff --git a/tests/RadioSelectableDataTable.test.svelte b/tests/RadioSelectableDataTable.test.svelte
index f4c2fdaa..9225f573 100644
--- a/tests/RadioSelectableDataTable.test.svelte
+++ b/tests/RadioSelectableDataTable.test.svelte
@@ -5,7 +5,7 @@
     { key: "name", value: "Name" },
     { key: "port", value: "Port" },
     { key: "rule", value: "Rule" },
-  ];
+  ] as const;
 
   const rows = [
     { id: "a", name: "Load Balancer 3", port: 3000, rule: "Round robin" },
diff --git a/tests/SelectableDataTable.test.svelte b/tests/SelectableDataTable.test.svelte
index 2424c7a2..ec6fec84 100644
--- a/tests/SelectableDataTable.test.svelte
+++ b/tests/SelectableDataTable.test.svelte
@@ -5,7 +5,7 @@
     { key: "name", value: "Name" },
     { key: "port", value: "Port" },
     { key: "rule", value: "Rule" },
-  ];
+  ] as const;
 
   const rows = [
     { id: "a", name: "Load Balancer 3", port: 3000, rule: "Round robin" },