diff --git a/lms/djangoapps/course_api/blocks/api.py b/lms/djangoapps/course_api/blocks/api.py
index a99fc4121d..905e1bd9d7 100644
--- a/lms/djangoapps/course_api/blocks/api.py
+++ b/lms/djangoapps/course_api/blocks/api.py
@@ -26,7 +26,7 @@ def get_blocks(
         student_view_data=None,
         return_type='dict',
         block_types_filter=None,
-        hide_access_denials=False,
+        hide_access_denials=True,
 ):
     """
     Return a serialized representation of the course blocks.
diff --git a/lms/djangoapps/course_blocks/transformers/access_denied_filter.py b/lms/djangoapps/course_blocks/transformers/access_denied_filter.py
index 5ca3125857..adbcd5f740 100644
--- a/lms/djangoapps/course_blocks/transformers/access_denied_filter.py
+++ b/lms/djangoapps/course_blocks/transformers/access_denied_filter.py
@@ -37,7 +37,4 @@ class AccessDeniedMessageFilterTransformer(BlockStructureTransformer):
             message = block_structure.get_xblock_field(block_key, 'authorization_denial_message')
             return reason and message
 
-        for _ in block_structure.post_order_traversal(
-            filter_func=block_structure.create_removal_filter(_filter)
-        ):
-            pass
+        block_structure.remove_block_traversal(_filter)