diff --git a/app/models.py b/app/models.py
index 032701e9..41f992ba 100644
--- a/app/models.py
+++ b/app/models.py
@@ -85,7 +85,7 @@ class Instance(db.Model):
     def votes_are_public(self):
         if self.trusted is True:    # only vote privately with untrusted instances
             return False
-        return self.software.lower() == 'lemmy' or self.software.lower() == 'mbin' or self.software.lower() == 'kbin'
+        return self.software.lower() == 'lemmy' or self.software.lower() == 'mbin' or self.software.lower() == 'kbin' or self.software.lower() == 'guppe groups'
 
     def post_count(self):
         return db.session.execute(text('SELECT COUNT(id) as c FROM "post" WHERE instance_id = :instance_id'),
diff --git a/app/post/routes.py b/app/post/routes.py
index 120faf1e..eb09185f 100644
--- a/app/post/routes.py
+++ b/app/post/routes.py
@@ -324,7 +324,11 @@ def post_vote(post_id: int, vote_direction):
                 if instance.inbox and not current_user.has_blocked_instance(instance.id) and not instance_banned(instance.domain):
                     send_to_remote_instance(instance.id, post.community.id, announce)
         else:
-            post_request_in_background(post.community.ap_inbox_url, action_json, current_user.private_key,
+            inbox = post.community.ap_inbox_url
+            if (post.community.ap_domain and post.author.ap_inbox_url and                    # sanity check these fields aren't null
+                post.community.ap_domain == 'a.gup.pe' and vote_direction == 'upvote'):      # send upvotes to post author's instance instead of a.gup.pe (who reject them)
+                inbox = post.author.ap_inbox_url
+            post_request_in_background(inbox, action_json, current_user.private_key,
                                        current_user.public_url(not(post.community.instance.votes_are_public() and current_user.vote_privately())) + '#main-key')
 
     recently_upvoted = []