diff --git a/patches/@tanstack__markdown@0.0.5.patch b/patches/@tanstack__markdown@0.0.5.patch
new file mode 100644
index 000000000..06842b19c
--- /dev/null
+++ b/patches/@tanstack__markdown@0.0.5.patch
@@ -0,0 +1,17 @@
+diff --git a/dist/parser.js b/dist/parser.js
+index 6616130a037737d109c527ec23ea8149ad8a68aa..be8c5b941d9437324b74f353fb3a51293a029740 100644
+--- a/dist/parser.js
++++ b/dist/parser.js
+@@ -334,9 +334,10 @@ function extractDefinitions(lines) {
+                 footnotes[normalizeReferenceLabel(label)] = { label, content: content.join('\n') };
+                 continue;
+             }
+-            const definition = line.match(/^ {0,3}\[([^\]\n]+)\]:[ \t]*(\S+)[ \t]*$/);
++            const definition = line.match(/^ {0,3}\[([^\]\n]+)\]:[ \t]*(\S+)(?:[ \t]+(?:"([^"]*)"|'([^']*)'|\(([^)]*)\)))?[ \t]*$/);
+             if (definition) {
+-                references[normalizeReferenceLabel(definition[1])] = { href: definition[2].replace(/^<|>$/g, '') };
++                const title = definition[3] ?? definition[4] ?? definition[5];
++                references[normalizeReferenceLabel(definition[1])] = { href: definition[2].replace(/^<|>$/g, ''), ...(title !== undefined ? { title } : {}) };
+                 index++;
+                 continue;
+             }
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index d935d005a..f784409b5 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -17,6 +17,9 @@ overrides:
   minimatch@10.2.5>brace-expansion: 5.0.5
   npm-run-path@6.0.0>unicorn-magic: 0.4.0
 
+patchedDependencies:
+  '@tanstack/markdown@0.0.5': 42bdbc7f0f0d0183adfdfc9c93d706e36a0b099c6bd25a2ad09e22ddc94e426e
+
 importers:
 
   .:
@@ -107,7 +110,7 @@ importers:
         version: 0.0.2
       '@tanstack/markdown':
         specifier: ^0.0.5
-        version: 0.0.5(react@19.2.3)
+        version: 0.0.5(patch_hash=42bdbc7f0f0d0183adfdfc9c93d706e36a0b099c6bd25a2ad09e22ddc94e426e)(react@19.2.3)
       '@tanstack/pacer':
         specifier: ^0.21.1
         version: 0.21.1
@@ -9668,7 +9671,7 @@ snapshots:
     dependencies:
       '@tanstack/store': 0.11.0
 
-  '@tanstack/markdown@0.0.5(react@19.2.3)':
+  '@tanstack/markdown@0.0.5(patch_hash=42bdbc7f0f0d0183adfdfc9c93d706e36a0b099c6bd25a2ad09e22ddc94e426e)(react@19.2.3)':
     optionalDependencies:
       react: 19.2.3
 
diff --git a/pnpm-workspace.yaml b/pnpm-workspace.yaml
index e6add2aca..aa58df881 100644
--- a/pnpm-workspace.yaml
+++ b/pnpm-workspace.yaml
@@ -33,3 +33,6 @@ allowBuilds:
 
   # Cloudflare Workers local runtime
   workerd: true
+
+patchedDependencies:
+  '@tanstack/markdown@0.0.5': patches/@tanstack__markdown@0.0.5.patch
diff --git a/tests/markdown-link-reference-definitions.test.ts b/tests/markdown-link-reference-definitions.test.ts
new file mode 100644
index 000000000..594380976
--- /dev/null
+++ b/tests/markdown-link-reference-definitions.test.ts
@@ -0,0 +1,132 @@
+import assert from 'node:assert/strict'
+import { parseSiteMarkdown } from '../src/utils/markdown'
+
+const markdownCases = [
+  {
+    name: 'single-quoted title',
+    markdown: "[//]: # 'SomeLabel'\n\nVisible content.",
+    referenceMarkdown:
+      "[example]: https://example.com 'Example title'\n\n[Example][example]",
+    title: 'Example title',
+  },
+  {
+    name: 'double-quoted title',
+    markdown: '[//]: # "SomeLabel"\n\nVisible content.',
+    referenceMarkdown:
+      '[example]: https://example.com "Example title"\n\n[Example][example]',
+    title: 'Example title',
+  },
+  {
+    name: 'parenthesized title',
+    markdown: '[//]: # (SomeLabel)\n\nVisible content.',
+    referenceMarkdown:
+      '[example]: https://example.com (Example title)\n\n[Example][example]',
+    title: 'Example title',
+  },
+]
+
+for (const testCase of markdownCases) {
+  const document = parseSiteMarkdown(testCase.markdown)
+
+  assert.equal(
+    document.children.length,
+    1,
+    `${testCase.name} reference definition is not rendered`,
+  )
+
+  const paragraph = document.children[0]
+
+  assert.equal(paragraph?.type, 'paragraph', `${testCase.name} content remains`)
+
+  if (paragraph?.type !== 'paragraph') {
+    throw new Error(`${testCase.name} did not produce a paragraph`)
+  }
+
+  assert.deepEqual(
+    paragraph.children,
+    [{ type: 'text', value: 'Visible content.' }],
+    `${testCase.name} visible paragraph is preserved`,
+  )
+
+  const commentReferenceDocument = parseSiteMarkdown(
+    `${testCase.markdown}\n\n[Example][//]`,
+  )
+  const commentReferenceParagraph = commentReferenceDocument.children[1]
+
+  assert.equal(
+    commentReferenceParagraph?.type,
+    'paragraph',
+    `${testCase.name} comment reference link paragraph is parsed`,
+  )
+
+  if (commentReferenceParagraph?.type !== 'paragraph') {
+    throw new Error(
+      `${testCase.name} did not produce a comment reference paragraph`,
+    )
+  }
+
+  const commentReferenceLink = commentReferenceParagraph.children[0]
+
+  assert.equal(
+    commentReferenceLink?.type,
+    'link',
+    `${testCase.name} comment reference link resolves`,
+  )
+
+  if (commentReferenceLink?.type !== 'link') {
+    throw new Error(`${testCase.name} did not produce a comment reference link`)
+  }
+
+  assert.equal(
+    commentReferenceLink.href,
+    '#',
+    `${testCase.name} comment reference link href is preserved`,
+  )
+
+  assert.equal(
+    commentReferenceLink.title,
+    'SomeLabel',
+    `${testCase.name} comment reference link title is preserved`,
+  )
+
+  const referenceDocument = parseSiteMarkdown(testCase.referenceMarkdown)
+  const referenceParagraph = referenceDocument.children[0]
+
+  assert.equal(
+    referenceParagraph?.type,
+    'paragraph',
+    `${testCase.name} reference link paragraph is parsed`,
+  )
+
+  if (referenceParagraph?.type !== 'paragraph') {
+    throw new Error(`${testCase.name} did not produce a reference paragraph`)
+  }
+
+  const link = referenceParagraph.children[0]
+
+  assert.equal(link?.type, 'link', `${testCase.name} reference link resolves`)
+
+  if (link?.type !== 'link') {
+    throw new Error(`${testCase.name} did not produce a reference link`)
+  }
+
+  assert.equal(
+    link.href,
+    'https://example.com',
+    `${testCase.name} reference link href is preserved`,
+  )
+
+  assert.equal(
+    link.title,
+    testCase.title,
+    `${testCase.name} reference link title is preserved`,
+  )
+
+  assert.deepEqual(
+    link.children,
+    [{ type: 'text', value: 'Example' }],
+    `${testCase.name} reference link label is preserved`,
+  )
+}
+
+console.log('markdown link reference definition tests passed')