diff --git a/src/theme/BlogPostItem/Header/index.tsx b/src/theme/BlogPostItem/Header/index.tsx
new file mode 100644
index 000000000..2ad61d1b6
--- /dev/null
+++ b/src/theme/BlogPostItem/Header/index.tsx
@@ -0,0 +1,31 @@
+import React, {type ReactNode} from 'react';
+import Header from '@theme-original/BlogPostItem/Header';
+import type HeaderType from '@theme/BlogPostItem/Header';
+import type {WrapperProps} from '@docusaurus/types';
+import {useBlogPost} from '@docusaurus/plugin-content-blog/client';
+import Admonition from '@theme/Admonition';
+
+type Props = WrapperProps<typeof HeaderType>;
+
+export default function HeaderWrapper(props: Props): ReactNode {
+  const { metadata: { date: postDate } } = useBlogPost();
+  
+  const postAgeInYears = Math.floor((Date.now() - new Date(postDate).getTime()) / (1000 * 60 * 60 * 24 * 365));
+
+  const postIsOld = postAgeInYears >= 1;
+
+  return (
+    <>
+      {
+        postIsOld ? (
+        <Admonition type="warning">
+          <p>
+            This blog post is over { postAgeInYears } { postAgeInYears === 1 ? 'year' : 'years' } old.
+          </p>
+        </Admonition>
+        ) : null
+      }
+      <Header {...props} />
+    </>
+  );
+}