diff --git a/profile2.install b/profile2.install
index 371ded1..c57e7e4 100644
--- a/profile2.install
+++ b/profile2.install
@@ -87,6 +87,9 @@ function profile2_schema() {
       ),
     ),
     'primary key' => array('pid'),
+    'unique keys' => array(
+      'vid' => array('vid'),
+    ),
   );
 
   $schema['profile_revision'] = _profile2_revision_table();
@@ -229,7 +232,7 @@ function _profile2_revision_table() {
       ),
       'version_uid' => array(
         'table' => 'users',
-        'columns' => array('authorid' => 'authorid'),
+        'columns' => array('authorid' => 'uid'),
       ),
     ),
   );