diff --git a/apps/journal/app/lib/federation.server.test.ts b/apps/journal/app/lib/federation.server.test.ts
index f00aa39..294ab08 100644
--- a/apps/journal/app/lib/federation.server.test.ts
+++ b/apps/journal/app/lib/federation.server.test.ts
@@ -95,12 +95,18 @@ describe("actor object", () => {
     expect(actor.preferredUsername).toBe("bruno");
     expect(actor.name).toBe("Bruno");
     expect(actor.summary).toBe("Riding bikes");
-    // Profile-metadata field Mastodon renders ("this is a trails profile")
-    const attachments = Array.isArray(actor.attachment) ? actor.attachment : [actor.attachment];
-    const field = attachments.find((a: { type: string }) => a?.type === "PropertyValue");
-    expect(field?.name).toBe("🥾 trails.cool");
-    expect(field?.value).toContain('href="http://localhost:3000/users/bruno"');
-    expect(field?.value).toContain('rel="me"');
+    // Profile-metadata fields Mastodon renders ("this is a trails
+    // profile"). MUST serialize as a JSON array — Mastodon's parser
+    // silently ignores a bare attachment object, which is what Fedify
+    // compacts single-element arrays into (hence two fields).
+    expect(Array.isArray(actor.attachment)).toBe(true);
+    const fields = actor.attachment.filter((a: { type: string }) => a?.type === "PropertyValue");
+    expect(fields.length).toBeGreaterThanOrEqual(2);
+    const trails = fields.find((f: { name: string }) => f.name === "🥾 trails.cool");
+    expect(trails?.value).toContain('href="http://localhost:3000/users/bruno"');
+    expect(trails?.value).toContain('rel="me"');
+    const instance = fields.find((f: { name: string }) => f.name === "Instance");
+    expect(instance?.value).toContain("localhost:3000");
   });
 
   it("404s the actor for a private user", async () => {
diff --git a/apps/journal/app/lib/federation.server.ts b/apps/journal/app/lib/federation.server.ts
index 6cb971e..8622653 100644
--- a/apps/journal/app/lib/federation.server.ts
+++ b/apps/journal/app/lib/federation.server.ts
@@ -180,11 +180,19 @@ function buildFederation(): Federation<void> {
         // metadata table — a human-visible "this is a trails profile"
         // marker. (The machine-readable marker is NodeInfo; this is
         // flair.) Mastodon strips most HTML in values but keeps links.
+        // NOTE: Mastodon's parser requires `attachment` to be a JSON
+        // *array* and silently ignores a bare object — and Fedify
+        // compacts single-element arrays to bare objects. Keep at least
+        // two fields here so the array survives serialization.
         attachments: [
           new PropertyValue({
             name: "🥾 trails.cool",
             value: `<a href="${localActorIri(identifier)}" rel="me">${getOrigin().replace(/^https?:\/\//, "")}/users/${identifier}</a>`,
           }),
+          new PropertyValue({
+            name: "Instance",
+            value: `<a href="${getOrigin()}">${getOrigin().replace(/^https?:\/\//, "")}</a>`,
+          }),
         ],
       });
     })