diff --git a/app/activitypub/util.py b/app/activitypub/util.py
index 74776ab3..9dff6708 100644
--- a/app/activitypub/util.py
+++ b/app/activitypub/util.py
@@ -140,7 +140,7 @@ def post_to_activity(post: Post, community: Community):
             "object": {
                 "type": "Page",
                 "id": post.ap_id,
-                "attributedTo": post.author.profile_id(),
+                "attributedTo": post.author.profile_id() if post.author.is_local() else post.author.ap_public_url,
                 "to": [
                     f"https://{current_app.config['SERVER_NAME']}/c/{community.name}",
                     "https://www.w3.org/ns/activitystreams#Public"
diff --git a/app/models.py b/app/models.py
index ac30fa65..4242e785 100644
--- a/app/models.py
+++ b/app/models.py
@@ -625,7 +625,7 @@ class User(UserMixin, db.Model):
 
     ap_id = db.Column(db.String(255), index=True)           # e.g. username@server
     ap_profile_id = db.Column(db.String(255), index=True)   # e.g. https://server/u/username
-    ap_public_url = db.Column(db.String(255))               # e.g. https://server/u/username
+    ap_public_url = db.Column(db.String(255))               # e.g. https://server/u/UserName
     ap_fetched_at = db.Column(db.DateTime)
     ap_followers_url = db.Column(db.String(255))
     ap_preferred_username = db.Column(db.String(255))