diff --git a/revisionreference.module b/revisionreference.module
index f330e9c..c09e2d5 100644
--- a/revisionreference.module
+++ b/revisionreference.module
@@ -27,6 +27,8 @@ function revisionreference_field_info() {
       'default_widget'      => 'options_select', 
       'default_formatter'   => 'revisionreference_default',
       'referenceable_types' => array(),
+      // Allow to work with the 'entity' module in a rudimentary way.
+      'property_type'       => 'integer',
     ),
   );
 }
\ No newline at end of file