diff --git a/lib/generate/activitypub.ts b/lib/generate/activitypub.ts
index 6de701a..6f36aaa 100644
--- a/lib/generate/activitypub.ts
+++ b/lib/generate/activitypub.ts
@@ -29,7 +29,11 @@ function postObject(post: Page): object {
 			"https://www.w3.org/ns/activitystreams"
 		],
 		"type": "Article",
-		"id": `https://${baseURL}${postMeta.permalink}.json`,
+		"id": `https://${baseURL}${path.format({
+			dir: path.dirname(post.metadata.permalink),
+			name: path.basename(post.metadata.permalink),
+			ext: ".json"
+		})}`,
 		"published": (<Date>postMeta.date).toISOString(),
 		"inReplyTo": null,
 		"url": `https://${baseURL}${postMeta.permalink}`,