diff --git a/lib/check/validate.js b/lib/check/validate.js
index a1b086d..71baa9e 100644
--- a/lib/check/validate.js
+++ b/lib/check/validate.js
@@ -127,6 +127,11 @@ function warn(ctx, reference) {
   let index = -1
 
   while (++index < reference.nodes.length) {
-    reference.file.message(reason, reference.nodes[index], origin)
+    const message = reference.file.message(
+      reason,
+      reference.nodes[index],
+      origin
+    )
+    message.url = 'https://github.com/remarkjs/remark-validate-links#readme'
   }
 }
diff --git a/test/index.js b/test/index.js
index 4169343..de50db3 100644
--- a/test/index.js
+++ b/test/index.js
@@ -41,6 +41,17 @@ test('remark-validate-links', async (t) => {
     ],
     'should work on the API'
   )
+  t.deepEqual(
+    vfile.messages.map((message) => message.url),
+    [
+      'https://github.com/remarkjs/remark-validate-links#readme',
+      'https://github.com/remarkjs/remark-validate-links#readme',
+      'https://github.com/remarkjs/remark-validate-links#readme',
+      'https://github.com/remarkjs/remark-validate-links#readme',
+      'https://github.com/remarkjs/remark-validate-links#readme'
+    ],
+    'should add message urls'
+  )
 
   const file = await remark()
     .use(links)