diff --git a/openedx/core/djangoapps/content/block_structure/store.py b/openedx/core/djangoapps/content/block_structure/store.py
index b6976046c4..7974a0d4f1 100644
--- a/openedx/core/djangoapps/content/block_structure/store.py
+++ b/openedx/core/djangoapps/content/block_structure/store.py
@@ -93,6 +93,7 @@ class BlockStructureStore(object):
             serialized_data = self._get_from_cache(bs_model)
         except BlockStructureNotFound:
             serialized_data = self._get_from_store(bs_model)
+            self._add_to_cache(serialized_data, bs_model)
 
         return self._deserialize(serialized_data, root_block_usage_key)