diff --git a/schemaorg.features.inc b/schemaorg.features.inc
index 98efd72..524ba95 100644
--- a/schemaorg.features.inc
+++ b/schemaorg.features.inc
@@ -90,6 +90,8 @@ function schemaorg_features_rebuild($module) {
   if ($defaults = features_get_default('schemaorg', $module)) {
     foreach ($defaults as $entity_type => $bundles) {
       foreach ($bundles as $bundle => $mapping) {
+        $current_mapping = rdf_mapping_load($entity_type, $bundle);
+        $mapping = array_merge($current_mapping, $mapping);
         rdf_mapping_save(array(
           'type' => $entity_type,
           'bundle' => $bundle,