diff --git a/app/activitypub/routes.py b/app/activitypub/routes.py
index 878f7d87..92b3cc06 100644
--- a/app/activitypub/routes.py
+++ b/app/activitypub/routes.py
@@ -1055,7 +1055,7 @@ def comment_ap(comment_id):
             }
         resp = jsonify(reply_data)
         resp.content_type = 'application/activity+json'
-        resp.headers.set('Vary', 'Accept, Cookie')
+        resp.headers.set('Vary', 'Accept, Accept-Encoding, Cookie')
         return resp
     else:
         reply = PostReply.query.get_or_404(comment_id)
@@ -1076,7 +1076,7 @@ def post_ap(post_id):
         post_data['@context'] = default_context()
         resp = jsonify(post_data)
         resp.content_type = 'application/activity+json'
-        resp.headers.set('Vary', 'Accept, Cookie')
+        resp.headers.set('Vary', 'Accept, Accept-Encoding, Cookie')
         return resp
     else:
         return show_post(post_id)
diff --git a/app/post/routes.py b/app/post/routes.py
index 3159af11..82ed87dc 100644
--- a/app/post/routes.py
+++ b/app/post/routes.py
@@ -182,7 +182,7 @@ def show_post(post_id: int):
                            joined_communities=joined_communities(current_user.get_id()),
                            inoculation=inoculation[randint(0, len(inoculation) - 1)]
                            )
-    response.headers.set('Vary', 'Accept, Cookie')
+    response.headers.set('Vary', 'Accept, Accept-Encoding, Cookie')
     return response
 
 
@@ -374,7 +374,8 @@ def continue_discussion(post_id, comment_id):
                            moderating_communities=moderating_communities(current_user.get_id()),
                            joined_communities=joined_communities(current_user.get_id()), community=post.community,
                            inoculation=inoculation[randint(0, len(inoculation) - 1)])
-    return response.headers.set('Vary', 'Accept, Cookie')
+    response.headers.set('Vary', 'Accept, Accept-Encoding, Cookie')
+    return response
 
 
 @bp.route('/post/<int:post_id>/comment/<int:comment_id>/reply', methods=['GET', 'POST'])
diff --git a/app/utils.py b/app/utils.py
index d721503f..508de99e 100644
--- a/app/utils.py
+++ b/app/utils.py
@@ -57,6 +57,7 @@ def return_304(etag, content_type=None):
     resp = make_response('', 304)
     resp.headers.add_header('ETag', request.headers['If-None-Match'])
     resp.headers.add_header('Cache-Control', 'no-cache, max-age=600, must-revalidate')
+    resp.headers.add_header('Vary', 'Accept, Accept-Encoding, Cookie')
     if content_type:
         resp.headers.set('Content-Type', content_type)
     return resp