diff --git node_reference/node_reference.module node_reference/node_reference.module
index 8c78bc0..51a0b92 100644
--- node_reference/node_reference.module
+++ node_reference/node_reference.module
@@ -35,6 +35,8 @@ function node_reference_field_info() {
       // 'instance settings' => array('referenceable_types' => array()),
       'default_widget'    => 'options_select', //  node_reference_autocomplete',
       'default_formatter' => 'node_reference_default',
+      // Support hook_entity_property_info() of the entity API module.
+      'property_type' => 'node',
     ),
   );
 }
diff --git user_reference/user_reference.module user_reference/user_reference.module
index e5749e5..b880063 100644
--- user_reference/user_reference.module
+++ user_reference/user_reference.module
@@ -31,6 +31,8 @@ function user_reference_field_info() {
       'settings' => array('referenceable_roles' => array(), 'referenceable_status' => array()),
       'default_widget' => 'user_reference_autocomplete',
       'default_formatter' => 'user_reference_default',
+      // Support hook_entity_property_info() of the entity API module.
+      'property_type' => 'user',
     ),
   );
 }