diff --git a/packages/craftcms-ui/src/components/tabs/tabs.browser.test.ts b/packages/craftcms-ui/src/components/tabs/tabs.browser.test.ts
index d9bc4f791bc..5fa1fbb5dcf 100644
--- a/packages/craftcms-ui/src/components/tabs/tabs.browser.test.ts
+++ b/packages/craftcms-ui/src/components/tabs/tabs.browser.test.ts
@@ -53,6 +53,18 @@ it('grows with its panels under a host that was not', async () => {
   expect(tabs.getBoundingClientRect().height).toBeGreaterThan(800);
 });
 
+it('weights the selected tab the same as its reserved label width', async () => {
+  const tabs = await fixture('display: block;');
+  const tab = tabs.querySelector<HTMLElement>('craft-tab')!;
+  const label = tab.shadowRoot!.querySelector<HTMLElement>('.tab__label')!;
+
+  expect(tab.hasAttribute('selected')).toBe(true);
+  expect(getComputedStyle(tab).fontWeight).toBe(
+    getComputedStyle(label, '::after').fontWeight
+  );
+  expect(getComputedStyle(tab).fontWeight).not.toBe('700');
+});
+
 it('scrolls its panels from the keyboard, leaving the strip in place', async () => {
   const tabs = await fixture('display: block; block-size: 300px;');
   const region = panels(tabs);
diff --git a/packages/craftcms-ui/src/components/tabs/tabs.styles.ts b/packages/craftcms-ui/src/components/tabs/tabs.styles.ts
index ddd7d893704..c5b16920637 100644
--- a/packages/craftcms-ui/src/components/tabs/tabs.styles.ts
+++ b/packages/craftcms-ui/src/components/tabs/tabs.styles.ts
@@ -67,6 +67,12 @@ export default css`
     flex: none;
   }
 
+  /* Overrides LionTabs' bold, which would otherwise beat the tab's own
+     selected weight and its width-reserving label copy. */
+  .tabs__tab-group ::slotted([slot='tab'][selected]) {
+    font-weight: var(--c-tab-font-weight-active, var(--font-weight-semibold));
+  }
+
   /*
    * Unless the strip is asked to divide its width evenly, which is the other
    * answer to the same problem: rather than collapsing the tabs that don't