diff --git a/app/activitypub/routes.py b/app/activitypub/routes.py
index 1db3c44b..d83b0759 100644
--- a/app/activitypub/routes.py
+++ b/app/activitypub/routes.py
@@ -1070,6 +1070,20 @@ def process_inbox_request(request_json, store_ap_json):
                         log_incoming_ap(request_json['id'], APLOG_UNDO_VOTE, APLOG_FAILURE, request_json if store_ap_json else None, 'Unfound object ' + target_ap_id)
                     return
 
+                if request_json['object']['object']['type'] == 'Lock':                                                                      # Announce of undo of post lock
+                    mod = user
+                    post_id = request_json['object']['object']['object']
+                    post = Post.query.filter_by(ap_id=post_id).first()
+                    if post:
+                        if post.community.is_moderator(mod) or post.community.is_instance_admin(mod):
+                            post.comments_enabled = True
+                            db.session.commit()
+                            log_incoming_ap(request_json['id'], APLOG_LOCK, APLOG_SUCCESS, request_json if store_ap_json else None)
+                        else:
+                            log_incoming_ap(request_json['id'], APLOG_LOCK, APLOG_FAILURE, request_json if store_ap_json else None, 'Lock: Does not have permission')
+                    else:
+                        log_incoming_ap(request_json['id'], APLOG_LOCK, APLOG_FAILURE, request_json if store_ap_json else None, 'Lock: post not found')
+                    return
 
 
         # -- below this point is code that will be incrementally replaced to use log_incoming_ap() instead --