diff --git a/requirements/edx/github.txt b/requirements/edx/github.txt
index 6ac60c7d71..d2f43a0f8d 100644
--- a/requirements/edx/github.txt
+++ b/requirements/edx/github.txt
@@ -26,3 +26,6 @@
 -e git+https://github.com/edx/bok-choy.git@25a47b3bf87c503fc4996e52addac83b42ec6f38#egg=bok_choy
 -e git+https://github.com/edx-solutions/django-splash.git@9965a53c269666a30bb4e2b3f6037c138aef2a55#egg=django-splash
 -e git+https://github.com/edx/acid-block.git@459aff7b63db8f2c5decd1755706c1a64fb4ebb1#egg=acid-xblock
+
+# Prototype XBlocks for limited roll-outs and user testing. These are not for general use. 
+-e git+https://github.com/pmitros/ConceptXBlock.git@2376fde9ebdd83684b78dde77ef96361c3bd1aa0#egg=concept-xblock