diff --git a/tildes/openapi_beta.yaml b/tildes/openapi_beta.yaml
index 436b571..5204d74 100644
--- a/tildes/openapi_beta.yaml
+++ b/tildes/openapi_beta.yaml
@@ -316,10 +316,13 @@ components:
           nullable: true
         voted:
           type: boolean
+          nullable: true
         bookmarked:
           type: boolean
+          nullable: true
         ignored:
           type: boolean
+          nullable: true
         official:
           type: boolean
         tags:
@@ -387,8 +390,10 @@ components:
           nullable: true
         voted:
           type: boolean
+          nullable: true
         bookmarked:
           type: boolean
+          nullable: true
         depth:
           type: integer
         children:
diff --git a/tildes/tildes/models/topic/topic_query.py b/tildes/tildes/models/topic/topic_query.py
index 0eb0d72..88694f9 100644
--- a/tildes/tildes/models/topic/topic_query.py
+++ b/tildes/tildes/models/topic/topic_query.py
@@ -142,7 +142,7 @@ class TopicQuery(PaginatedQuery):
             topic.bookmark_created_time = None
             topic.last_visit_time = None
             topic.comments_since_last_visit = None
-            topic.user_bookmarked = False
+            topic.user_bookmarked = None
             topic.user_ignored = False
         else:
             topic = result.Topic
diff --git a/tildes/tildes/views/api/beta/topic.py b/tildes/tildes/views/api/beta/topic.py
index 02a40f7..b8c87f3 100644
--- a/tildes/tildes/views/api/beta/topic.py
+++ b/tildes/tildes/views/api/beta/topic.py
@@ -60,7 +60,8 @@ def get_topics(request: Request) -> dict:  # noqa
 
     # Parse parameters where necessary
     try:
-        period = ShortTimePeriod(allow_none=True).deserialize(period_raw)
+        period = ShortTimePeriod(allow_none=True)
+        period = period.deserialize(period_raw)
     except ValidationError as exc:
         return build_error_response(str(exc), field="period")
 
@@ -127,10 +128,11 @@ def get_topic(request: Request) -> dict:
                 f"Invalid order value: {comment_order_raw}",
                 field="order",
             )
-    elif request.user and request.user.comment_sort_order_default:
-        comment_order = request.user.comment_sort_order_default
     else:
-        comment_order = CommentTreeSortOption.RELEVANCE
+        if request.user and request.user.comment_sort_order_default:
+            comment_order = request.user.comment_sort_order_default
+        else:
+            comment_order = CommentTreeSortOption.RELEVANCE
 
     try:
         topic_id = id36_to_id(topic_id36)
@@ -155,17 +157,15 @@ def get_topic(request: Request) -> dict:
     tree = CommentTree(comments, comment_order, request.user)
     tree.collapse_from_labels()
 
-    # collapse old comments if the user has a previous visit to the topic
-    # (and doesn't have that behavior disabled)
-    if request.user and topic.last_visit_time and request.user.collapse_old_comments:
-        tree.uncollapse_new_comments(topic.last_visit_time)
-        tree.finalize_collapsing_maximized()
+    if request.user:
+        # collapse old comments if the user has a previous visit to the topic
+        # (and doesn't have that behavior disabled)
+        if topic.last_visit_time and request.user.collapse_old_comments:
+            tree.uncollapse_new_comments(topic.last_visit_time)
+            tree.finalize_collapsing_maximized()
 
     commentsjson = comment_subtree_to_dict(request, tree.tree)
 
     # Construct the final response JSON object
-    response = {
-        "topic": topic_to_dict(topic),
-        "comments": commentsjson,
-    }
+    response = {"topic": topic_to_dict(topic), "comments": commentsjson}
     return response