diff --git a/playbooks/roles/edxapp/defaults/main.yml b/playbooks/roles/edxapp/defaults/main.yml
index 65d3c1af881..8c4e8ab2f5f 100644
--- a/playbooks/roles/edxapp/defaults/main.yml
+++ b/playbooks/roles/edxapp/defaults/main.yml
@@ -523,7 +523,7 @@ EDXAPP_EXTRA_REQUIREMENTS: []
 #   - name: git+https://git.myproject.org/MyProject#egg=MyProject
 EDXAPP_PRIVATE_REQUIREMENTS:
     # For Harvard courses:
-    - name: xblock-problem-builder==3.1.3
+    - name: xblock-problem-builder==4.1.8
     # Oppia XBlock
     - name: git+https://github.com/oppia/xblock.git@9f6b95b7eb7dbabb96b77198a3202604f96adf65#egg=oppia-xblock
       extra_args: -e