diff --git a/src/components/runners/ThFilterGroup.svelte b/src/components/runners/ThFilterGroup.svelte
index 50d4aab8..58764f44 100644
--- a/src/components/runners/ThFilterGroup.svelte
+++ b/src/components/runners/ThFilterGroup.svelte
@@ -5,7 +5,7 @@
   let selected = "all";
 </script>
 
-<th>
+<th style="border-bottom: 1px solid #ddd;">
   <select
     on:input={() => {
       setTimeout(() => {