diff --git a/cms/djangoapps/contentstore/views/preview.py b/cms/djangoapps/contentstore/views/preview.py
index 45ad7a7424..fa99aa5545 100644
--- a/cms/djangoapps/contentstore/views/preview.py
+++ b/cms/djangoapps/contentstore/views/preview.py
@@ -107,7 +107,7 @@ def preview_module_system(request, preview_id, descriptor):
         ajax_url=reverse('preview_dispatch', args=[preview_id, descriptor.location.url(), '']).rstrip('/'),
         # TODO (cpennington): Do we want to track how instructors are using the preview problems?
         track_function=lambda event_type, event: None,
-        filestore=descriptor.system.resources_fs,
+        filestore=descriptor.runtime.resources_fs,
         get_module=partial(load_preview_module, request, preview_id),
         render_template=render_from_lms,
         debug=True,
diff --git a/common/lib/xmodule/xmodule/error_module.py b/common/lib/xmodule/xmodule/error_module.py
index 2013ee2003..5c13b90ccf 100644
--- a/common/lib/xmodule/xmodule/error_module.py
+++ b/common/lib/xmodule/xmodule/error_module.py
@@ -129,7 +129,7 @@ class ErrorDescriptor(ErrorFields, XModuleDescriptor):
     @classmethod
     def from_descriptor(cls, descriptor, error_msg='Error not available'):
         return cls._construct(
-            descriptor.system,
+            descriptor.runtime,
             str(descriptor),
             error_msg,
             location=descriptor.location,
diff --git a/common/lib/xmodule/xmodule/tests/test_error_module.py b/common/lib/xmodule/xmodule/tests/test_error_module.py
index 186754e16c..5a47091045 100644
--- a/common/lib/xmodule/xmodule/tests/test_error_module.py
+++ b/common/lib/xmodule/xmodule/tests/test_error_module.py
@@ -37,7 +37,7 @@ class TestErrorModule(unittest.TestCase, SetupTestErrorModules):
 
     def test_error_module_from_descriptor(self):
         descriptor = MagicMock([XModuleDescriptor],
-                               system=self.system,
+                               runtime=self.system,
                                location=self.location,
                                _field_data=self.valid_xml)
 
@@ -72,7 +72,7 @@ class TestNonStaffErrorModule(unittest.TestCase, SetupTestErrorModules):
 
     def test_error_module_from_descriptor(self):
         descriptor = MagicMock([XModuleDescriptor],
-                               system=self.system,
+                               runtime=self.system,
                                location=self.location,
                                _field_data=self.valid_xml)
 
diff --git a/lms/djangoapps/courseware/module_render.py b/lms/djangoapps/courseware/module_render.py
index dc87bd8c0e..f752a402e4 100644
--- a/lms/djangoapps/courseware/module_render.py
+++ b/lms/djangoapps/courseware/module_render.py
@@ -344,7 +344,7 @@ def get_module_for_descriptor_internal(user, descriptor, field_data_cache, cours
         ajax_url=ajax_url,
         xqueue=xqueue,
         # TODO (cpennington): Figure out how to share info between systems
-        filestore=descriptor.system.resources_fs,
+        filestore=descriptor.runtime.resources_fs,
         get_module=inner_get_module,
         user=user,
         debug=settings.DEBUG,