diff --git a/html/semantics/forms/the-select-element/stylable-select/option-computed-style.tentative.html b/html/semantics/forms/the-select-element/stylable-select/option-computed-style.tentative.html
new file mode 100644
index 000000000000000..14650f3f320ae6f
--- /dev/null
+++ b/html/semantics/forms/the-select-element/stylable-select/option-computed-style.tentative.html
@@ -0,0 +1,17 @@
+<!DOCTYPE html>
+<link rel=author href="mailto:jarhar@chromium.org">
+<link rel=help href="https://github.com/openui/open-ui/issues/863#issuecomment-1769004174">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<select style="appearance:base-select">
+  <option>option</option>
+</select>
+
+<script>
+test(() => {
+  assert_equals(
+    getComputedStyle(document.querySelector('option'), '::before').content,
+    `"\u2713" / ""`);
+}, 'appearance:base-select options should have a checkmark with empty alt text.');
+</script>
diff --git a/html/semantics/forms/the-select-element/stylable-select/resources/stylable-select-styles.css b/html/semantics/forms/the-select-element/stylable-select/resources/stylable-select-styles.css
index 7f4c8b6c448af5a..0052b3863e2ef5d 100644
--- a/html/semantics/forms/the-select-element/stylable-select/resources/stylable-select-styles.css
+++ b/html/semantics/forms/the-select-element/stylable-select/resources/stylable-select-styles.css
@@ -38,6 +38,13 @@
   align-content: center;
 }
 
+.stylable-select-option::before {
+  content: '\2713' / '';
+}
+.stylable-select-option:not(.selected)::before {
+  visibility: hidden;
+}
+
 .stylable-select-button {
   color: FieldText;
   background-color: Field;
diff --git a/html/semantics/forms/the-select-element/stylable-select/select-child-button-and-datalist-ref.html b/html/semantics/forms/the-select-element/stylable-select/select-child-button-and-datalist-ref.html
index e99ca4d57a8b2e3..a27e662b1c4caba 100644
--- a/html/semantics/forms/the-select-element/stylable-select/select-child-button-and-datalist-ref.html
+++ b/html/semantics/forms/the-select-element/stylable-select/select-child-button-and-datalist-ref.html
@@ -10,7 +10,7 @@
 <div id=container class=stylable-select-container>
   <button popovertarget=popover id=button>button</button>
   <div id=popover popover=auto anchor=container class=stylable-select-datalist>
-    <div tabindex=0 class=stylable-select-option>
+    <div tabindex=0 class="stylable-select-option selected">
       <span class=blue>option</span> one
     </div>
     <div tabindex=0 class=stylable-select-option>
diff --git a/html/semantics/forms/the-select-element/stylable-select/select-open-invalidation-ref.html b/html/semantics/forms/the-select-element/stylable-select/select-open-invalidation-ref.html
index f5b70c495bc82a0..fb609a7247e6413 100644
--- a/html/semantics/forms/the-select-element/stylable-select/select-open-invalidation-ref.html
+++ b/html/semantics/forms/the-select-element/stylable-select/select-open-invalidation-ref.html
@@ -10,7 +10,7 @@
 <div id=container class=stylable-select-container>
   <button>button</button>
   <div id=popover popover=auto anchor=container class=stylable-select-datalist>
-    <div tabindex=0 class=stylable-select-option>one</div>
+    <div tabindex=0 class="stylable-select-option selected">one</div>
     <div class=stylable-select-option>two</div>
   </div>
 </div>
