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',
     ),
   );
 }
@@ -593,4 +595,4 @@ function revisionreference_vid_is_current($vid, $nid = NULL) {
  */
 function revisionreference_autocomplete_access($entity_type, $field_name) {
   return user_access('access content') && ($field = field_info_field($field_name)) && field_access('view', $field, $entity_type) && field_access('edit', $field, $entity_type);
-}
\ No newline at end of file
+}