diff --git a/src/runtime/markdown-parser/handler/html.ts b/src/runtime/markdown-parser/handler/html.ts
index ba4eff9cf..036aef31b 100644
--- a/src/runtime/markdown-parser/handler/html.ts
+++ b/src/runtime/markdown-parser/handler/html.ts
@@ -6,7 +6,7 @@ import { getTagName } from './utils'
 export default function html (h: H, node: any) {
   const tagName = getTagName(node.value)
 
-  if (tagName) {
+  if (tagName && /[A-Z]/.test(tagName)) {
     node.value = node.value.replace(tagName, kebabCase(tagName))
   }
 
diff --git a/test/features/parser-markdown.ts b/test/features/parser-markdown.ts
index 39bd03e32..d73a54234 100644
--- a/test/features/parser-markdown.ts
+++ b/test/features/parser-markdown.ts
@@ -68,5 +68,19 @@ export const testMarkdownParser = () => {
       expect(parsed.body).toHaveProperty('children')
       expect(parsed.body.children.length).toEqual(0)
     })
+
+    test('h1 tags', async () => {
+      const parsed = await $fetch('/api/parse', {
+        method: 'POST',
+        body: {
+          id: 'content:index.md',
+          content: '<h1>Hello</h1>'
+        }
+      })
+
+      expect(parsed.body).toHaveProperty('children')
+      expect(parsed.body.children.length).toEqual(1)
+      expect(parsed.body.children[0].tag).toEqual('h1')
+    })
   })
 }