diff --git a/packages/playwright-core/src/server/injected/selectorGenerator.ts b/packages/playwright-core/src/server/injected/selectorGenerator.ts
index 06ba6c13c0..93e2526213 100644
--- a/packages/playwright-core/src/server/injected/selectorGenerator.ts
+++ b/packages/playwright-core/src/server/injected/selectorGenerator.ts
@@ -224,7 +224,7 @@ function cssFallback(injectedScript: InjectedScript, targetElement: Element, str
     const path = tokens.slice();
     if (prefix)
       path.unshift(prefix);
-    const selector = path.join(' ');
+    const selector = path.join(' > ');
     const parsedSelector = injectedScript.parseSelector(selector);
     const node = injectedScript.querySelector(parsedSelector, targetElement.ownerDocument, false);
     return node === targetElement ? selector : undefined;
diff --git a/tests/library/selector-generator.spec.ts b/tests/library/selector-generator.spec.ts
index 95b7cae875..cef94b4d24 100644
--- a/tests/library/selector-generator.spec.ts
+++ b/tests/library/selector-generator.spec.ts
@@ -191,7 +191,28 @@ it.describe('selector generator', () => {
       </a>
       <a><b></b></a>
     `);
-    expect(await generate(page, 'c[mark="1"]')).toBe('b:nth-child(2) c');
+    expect(await generate(page, 'c[mark="1"]')).toBe('b:nth-child(2) > c');
+  });
+
+  it('should properly join child selectors under nested ordinals', async ({ page }) => {
+    await page.setContent(`
+      <a><c></c><c></c><c></c><c></c><c></c><b></b></a>
+      <a>
+        <b>
+          <div>
+            <c>
+            </c>
+          </div>
+        </b>
+        <b>
+          <div>
+            <c mark=1></c>
+          </div>
+        </b>
+      </a>
+      <a><b></b></a>
+    `);
+    expect(await generate(page, 'c[mark="1"]')).toBe('b:nth-child(2) > div > c');
   });
 
   it('should not use input[value]', async ({ page }) => {
diff --git a/tests/page/page-strict.spec.ts b/tests/page/page-strict.spec.ts
index fc64cc1914..9a90cdc8fd 100644
--- a/tests/page/page-strict.spec.ts
+++ b/tests/page/page-strict.spec.ts
@@ -57,3 +57,30 @@ it('should fail page.dispatchEvent in strict mode', async ({ page }) => {
   expect(error.message).toContain('1) <span></span> aka playwright.$("span >> nth=0")');
   expect(error.message).toContain('2) <span></span> aka playwright.$("div span")');
 });
+
+it('should properly format :nth-child() in strict mode message', async ({ page }) => {
+  await page.setContent(`
+  <div>
+    <div>
+    </div>
+    <div>
+      <div>
+      </div>
+      <div>
+      </div>
+    </div>
+  </div>
+  <div>
+    <div class='foo'>
+    </div>
+    <div class='foo'>
+    </div>
+  </div>
+  `);
+  const error = await page.locator('.foo').hover().catch(e => e);
+  console.log(error.message);
+  expect(error.message).toContain('strict mode violation');
+  // Second div has body > div:nth-child(2) > div:nth-child(2) selector which would be ambiguous
+  // if '>' were ' '.
+  expect(error.message).toContain('body > div:nth-child(2) > div:nth-child(2)');
+});