[#8356] pickle.loads uses bytes
diff --git a/Allura/allura/model/index.py b/Allura/allura/model/index.py
index 6bf0dfa..e22c8da 100644
--- a/Allura/allura/model/index.py
+++ b/Allura/allura/model/index.py
@@ -99,7 +99,7 @@
         '''Look up the artifact referenced'''
         aref = self.artifact_reference
         try:
-            cls = loads(str(aref.cls))
+            cls = loads(six.binary_type(aref.cls))
             with h.push_context(aref.project_id):
                 return cls.query.get(_id=aref.artifact_id)
         except: