diff --git a/packages/bbui/src/Form/Core/Checkbox.svelte b/packages/bbui/src/Form/Core/Checkbox.svelte
index 36ab9d288e..3efc737bfb 100644
--- a/packages/bbui/src/Form/Core/Checkbox.svelte
+++ b/packages/bbui/src/Form/Core/Checkbox.svelte
@@ -20,11 +20,10 @@
 </script>
 
 <label
-  class="spectrum-Checkbox spectrum-Checkbox--emphasized {sizeClass} {indeterminate
-    ? 'is-indeterminate'
-    : ''}"
+  class="spectrum-Checkbox spectrum-Checkbox--emphasized {sizeClass}"
   class:is-invalid={!!error}
   class:checked={value}
+  class:is-indeterminate={indeterminate}
 >
   <input
     checked={value}