diff --git a/common/lib/xmodule/xmodule/modulestore/tests/test_cross_modulestore_import_export.py b/common/lib/xmodule/xmodule/modulestore/tests/test_cross_modulestore_import_export.py
index 9245a62169..f3cdd87694 100644
--- a/common/lib/xmodule/xmodule/modulestore/tests/test_cross_modulestore_import_export.py
+++ b/common/lib/xmodule/xmodule/modulestore/tests/test_cross_modulestore_import_export.py
@@ -28,6 +28,8 @@ from xmodule.modulestore.xml_importer import import_from_xml
 from xmodule.modulestore.xml_exporter import export_to_xml
 from xmodule.modulestore.split_mongo.split_draft import DraftVersioningModuleStore
 from xmodule.modulestore.tests.mongo_connection import MONGO_PORT_NUM, MONGO_HOST
+from xmodule.modulestore.inheritance import InheritanceMixin
+from xmodule.x_module import XModuleMixin
 
 
 COMMON_DOCSTORE_CONFIG = {
@@ -36,6 +38,9 @@ COMMON_DOCSTORE_CONFIG = {
 }
 
 
+XBLOCK_MIXINS = (InheritanceMixin, XModuleMixin)
+
+
 class MemoryCache(object):
     """
     This fits the metadata_inheritance_cache_subsystem interface used by
@@ -95,6 +100,7 @@ class MongoModulestoreBuilder(object):
             render_template=repr,
             branch_setting_func=lambda: ModuleStoreEnum.Branch.draft_preferred,
             metadata_inheritance_cache_subsystem=MemoryCache(),
+            xblock_mixins=XBLOCK_MIXINS,
         )
         modulestore.ensure_indexes()
 
@@ -139,6 +145,7 @@ class VersioningModulestoreBuilder(object):
             doc_store_config,
             fs_root,
             render_template=repr,
+            xblock_mixins=XBLOCK_MIXINS,
         )
         modulestore.ensure_indexes()
 
@@ -189,7 +196,13 @@ class MixedModulestoreBuilder(object):
             # Generate a fake list of stores to give the already generated stores appropriate names
             stores = [{'NAME': name, 'ENGINE': 'This space deliberately left blank'} for name in names]
 
-            modulestore = MixedModuleStore(contentstore, self.mappings, stores, create_modulestore_instance=create_modulestore_instance)
+            modulestore = MixedModuleStore(
+                contentstore,
+                self.mappings,
+                stores,
+                create_modulestore_instance=create_modulestore_instance,
+                xblock_mixins=XBLOCK_MIXINS,
+            )
 
             yield modulestore
 
diff --git a/common/lib/xmodule/xmodule/modulestore/tests/test_mixed_modulestore.py b/common/lib/xmodule/xmodule/modulestore/tests/test_mixed_modulestore.py
index 8b6f6e32c1..a355068b69 100644
--- a/common/lib/xmodule/xmodule/modulestore/tests/test_mixed_modulestore.py
+++ b/common/lib/xmodule/xmodule/modulestore/tests/test_mixed_modulestore.py
@@ -18,6 +18,7 @@ from uuid import uuid4
 # TODO remove this import and the configuration -- xmodule should not depend on django!
 from django.conf import settings
 from xmodule.modulestore.edit_info import EditInfoMixin
+from xmodule.modulestore.inheritance import InheritanceMixin
 
 if not settings.configured:
     settings.configure()
@@ -58,7 +59,7 @@ class TestMixedModuleStore(unittest.TestCase):
         'default_class': DEFAULT_CLASS,
         'fs_root': DATA_DIR,
         'render_template': RENDER_TEMPLATE,
-        'xblock_mixins': (EditInfoMixin,)
+        'xblock_mixins': (EditInfoMixin, InheritanceMixin),
     }
     DOC_STORE_CONFIG = {
         'host': HOST,