diff --git a/opencloud.spec b/opencloud.spec
index 7fe1605..412a3f3 100644
--- a/opencloud.spec
+++ b/opencloud.spec
@@ -31,7 +31,7 @@
 
 %pre
 pip-python install django==1.7
-pip-python install djangorestframework
+pip-python install djangorestframework==2.4.4
 pip-python install markdown  # Markdown support for the browseable API.
 pip-python install pyyaml    # YAML content-type support.
 pip-python install django-filter  # Filtering support
diff --git a/planetstack/core/xoslib/static/js/xoslib/xos-backbone.js b/planetstack/core/xoslib/static/js/xoslib/xos-backbone.js
index b0ee0dc..0651709 100644
--- a/planetstack/core/xoslib/static/js/xoslib/xos-backbone.js
+++ b/planetstack/core/xoslib/static/js/xoslib/xos-backbone.js
@@ -361,11 +361,11 @@
             }
         }
 
-        if (xosdefaults && xosdefaults[modelName]) {
+        if ((typeof xosdefaults !== "undefined") && xosdefaults[modelName]) {
             modelAttrs["defaults"] = xosdefaults[modelName];
         }
 
-        if (xosvalidators && xosvalidators[modelName]) {
+        if ((typeof xosvalidators !== "undefined") && xosvalidators[modelName]) {
             modelAttrs["validators"] = xosvalidators[modelName];
         }